coccinelle: make use of SYNTHETIC_ERRNO

Ideally, coccinelle would strip unnecessary braces too. But I do not see any
option in coccinelle for this, so instead, I edited the patch text using
search&replace to remove the braces. Unfortunately this is not fully automatic,
in particular it didn't deal well with if-else-if-else blocks and ifdefs, so
there is an increased likelikehood be some bugs in such spots.

I also removed part of the patch that coccinelle generated for udev, where we
returns -1 for failure. This should be fixed independently.

src/basic/cgroup-util.c

@@ -2545,11 +2545,10 @@ static int cg_unified_update(void) {
                                 unified_cache = CGROUP_UNIFIED_NONE;
                         }
                 }
-        } else {
-                log_debug("Unknown filesystem type %llx mounted on /sys/fs/cgroup.",
-                          (unsigned long long) fs.f_type);
-                return -ENOMEDIUM;
-        }
+        } else
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM),
+                                       "Unknown filesystem type %llx mounted on /sys/fs/cgroup.",
+                                       (unsigned long long)fs.f_type);
 
         return 0;
 }

src/basic/fileio.c

@@ -638,16 +638,18 @@ static int check_utf8ness_and_warn(
                 _cleanup_free_ char *p = NULL;
 
                 p = utf8_escape_invalid(key);
-                log_error("%s:%u: invalid UTF-8 in key '%s', ignoring.", strna(filename), line, p);
-                return -EINVAL;
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "%s:%u: invalid UTF-8 in key '%s', ignoring.",
+                                       strna(filename), line, p);
         }
 
         if (value && !utf8_is_valid(value)) {
                 _cleanup_free_ char *p = NULL;
 
                 p = utf8_escape_invalid(value);
-                log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, p);
-                return -EINVAL;
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.",
+                                       strna(filename), line, key, p);
         }
 
         return 0;

src/basic/log.h

@@ -202,10 +202,10 @@ void log_assert_failed_return_realm(
 #define log_full_errno_realm(realm, level, error, ...)                  \
         ({                                                              \
                 int _level = (level), _e = (error), _realm = (realm);   \
-                (log_get_max_level_realm(_realm) >= LOG_PRI(_level))   \
+                (log_get_max_level_realm(_realm) >= LOG_PRI(_level))    \
                         ? log_internal_realm(LOG_REALM_PLUS_LEVEL(_realm, _level), _e, \
                                              __FILE__, __LINE__, __func__, __VA_ARGS__) \
-                        : -abs(_e);                                     \
+                        : -ERRNO_VALUE(_e);                             \
         })
 
 #define log_full_errno(level, error, ...)                               \

src/basic/process-util.c

@@ -1227,8 +1227,7 @@ int must_be_root(void) {
         if (geteuid() == 0)
                 return 0;
 
-        log_error("Need to be root.");
-        return -EPERM;
+        return log_error_errno(SYNTHETIC_ERRNO(EPERM), "Need to be root.");
 }
 
 int safe_fork_full(

src/basic/rm-rf.c

@@ -168,10 +168,10 @@ int rm_rf(const char *path, RemoveFlags flags) {
         /* We refuse to clean the root file system with this
          * call. This is extra paranoia to never cause a really
          * seriously broken system. */
-        if (path_equal_or_files_same(path, "/", AT_SYMLINK_NOFOLLOW)) {
-                log_error("Attempted to remove entire root file system (\"%s\"), and we can't allow that.", path);
-                return -EPERM;
-        }
+        if (path_equal_or_files_same(path, "/", AT_SYMLINK_NOFOLLOW))
+                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+                                       "Attempted to remove entire root file system (\"%s\"), and we can't allow that.",
+                                       path);
 
         if (FLAGS_SET(flags, REMOVE_SUBVOLUME | REMOVE_ROOT | REMOVE_PHYSICAL)) {
                 /* Try to remove as subvolume first */
@@ -194,10 +194,10 @@ int rm_rf(const char *path, RemoveFlags flags) {
                         if (statfs(path, &s) < 0)
                                 return -errno;
 
-                        if (is_physical_fs(&s)) {
-                                log_error("Attempted to remove files from a disk file system under \"%s\", refusing.", path);
-                                return -EPERM;
-                        }
+                        if (is_physical_fs(&s))
+                                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+                                                       "Attempted to remove files from a disk file system under \"%s\", refusing.",
+                                                       path);
                 }
 
                 if ((flags & REMOVE_ROOT) && !(flags & REMOVE_ONLY_DIRECTORIES))