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/libsystemd/sd-bus/bus-message.c

@@ -3832,11 +3832,13 @@ static int build_struct_offsets(
                                         x = size - (n_variable * sz);
 
                                 offset = m->rindex + x;
-                                if (offset < start) {
-                                        log_debug("For type %s with alignment %zu, message specifies offset %zu which is smaller than previous end %zu + alignment = %zu",
-                                                  t, align, offset, previous, start);
-                                        return -EBADMSG;
-                                }
+                                if (offset < start)
+                                        return log_debug_errno(SYNTHETIC_ERRNO(EBADMSG),
+                                                               "For type %s with alignment %zu, message specifies offset %zu which is smaller than previous end %zu + alignment = %zu",
+                                                               t, align,
+                                                               offset,
+                                                               previous,
+                                                               start);
                         } else
                                 /* Fixed size */
                                 offset = start + k;

src/libsystemd/sd-device/sd-device.c

@@ -137,10 +137,10 @@ int device_set_syspath(sd_device *device, const char *_syspath, bool verify) {
         assert(_syspath);
 
         /* must be a subdirectory of /sys */
-        if (!path_startswith(_syspath, "/sys/")) {
-                log_debug("sd-device: Syspath '%s' is not a subdirectory of /sys", _syspath);
-                return -EINVAL;
-        }
+        if (!path_startswith(_syspath, "/sys/"))
+                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "sd-device: Syspath '%s' is not a subdirectory of /sys",
+                                       _syspath);
 
         if (verify) {
                 r = chase_symlinks(_syspath, NULL, 0, &syspath);
@@ -159,10 +159,10 @@ int device_set_syspath(sd_device *device, const char *_syspath, bool verify) {
                                 return log_debug_errno(r, "sd-device: Failed to chase symlink /sys: %m");
 
                         p = path_startswith(syspath, real_sys);
-                        if (!p) {
-                                log_debug("sd-device: Canonicalized path '%s' does not starts with sysfs mount point '%s'", syspath, real_sys);
-                                return -ENODEV;
-                        }
+                        if (!p)
+                                return log_debug_errno(SYNTHETIC_ERRNO(ENODEV),
+                                                       "sd-device: Canonicalized path '%s' does not starts with sysfs mount point '%s'",
+                                                       syspath, real_sys);
 
                         new_syspath = strjoin("/sys/", p);
                         if (!new_syspath)

src/libsystemd/sd-netlink/sd-netlink.c

@@ -224,10 +224,10 @@ int sd_netlink_send(sd_netlink *nl,
 int rtnl_rqueue_make_room(sd_netlink *rtnl) {
         assert(rtnl);
 
-        if (rtnl->rqueue_size >= RTNL_RQUEUE_MAX) {
-                log_debug("rtnl: exhausted the read queue size (%d)", RTNL_RQUEUE_MAX);
-                return -ENOBUFS;
-        }
+        if (rtnl->rqueue_size >= RTNL_RQUEUE_MAX)
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOBUFS),
+                                       "rtnl: exhausted the read queue size (%d)",
+                                       RTNL_RQUEUE_MAX);
 
         if (!GREEDY_REALLOC(rtnl->rqueue, rtnl->rqueue_allocated, rtnl->rqueue_size + 1))
                 return -ENOMEM;
@@ -238,10 +238,10 @@ int rtnl_rqueue_make_room(sd_netlink *rtnl) {
 int rtnl_rqueue_partial_make_room(sd_netlink *rtnl) {
         assert(rtnl);
 
-        if (rtnl->rqueue_partial_size >= RTNL_RQUEUE_MAX) {
-                log_debug("rtnl: exhausted the partial read queue size (%d)", RTNL_RQUEUE_MAX);
-                return -ENOBUFS;
-        }
+        if (rtnl->rqueue_partial_size >= RTNL_RQUEUE_MAX)
+                return log_debug_errno(SYNTHETIC_ERRNO(ENOBUFS),
+                                       "rtnl: exhausted the partial read queue size (%d)",
+                                       RTNL_RQUEUE_MAX);
 
         if (!GREEDY_REALLOC(rtnl->rqueue_partial, rtnl->rqueue_partial_allocated,
                             rtnl->rqueue_partial_size + 1))