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/cryptsetup/cryptsetup-generator.c

@@ -123,10 +123,10 @@ static int create_disk(
         swap = fstab_test_option(options, "swap\0");
         netdev = fstab_test_option(options, "_netdev\0");
 
-        if (tmp && swap) {
-                log_error("Device '%s' cannot be both 'tmp' and 'swap'. Ignoring.", name);
-                return -EINVAL;
-        }
+        if (tmp && swap)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Device '%s' cannot be both 'tmp' and 'swap'. Ignoring.",
+                                       name);
 
         name_escaped = specifier_escape(name);
         if (!name_escaped)
@@ -158,10 +158,9 @@ static int create_disk(
                         return log_oom();
         }
 
-        if (keydev && !password) {
-                log_error("Key device is specified, but path to the password file is missing.");
-                return -EINVAL;
-        }
+        if (keydev && !password)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Key device is specified, but path to the password file is missing.");
 
         r = generator_open_unit_file(arg_dest, NULL, n, &f);
         if (r < 0)