treewide: yet more log_*_errno + return simplifications

Using:
find . -name '*.[ch]' | while read f; do perl -i.mmm -e \
 'local $/;
  local $_=<>;
  s/(if\s*\([^\n]+\))\s*{\n(\s*)(log_[a-z_]*_errno\(\s*([->a-zA-Z_]+)\s*,[^;]+);\s*return\s+\g4;\s+}/\1\n\2return \3;/msg;
  print;'
 $f
done

And a couple of manual whitespace fixups.

src/shared/generator.c

@@ -54,10 +54,8 @@ int generator_write_fsck_deps(
                         /* treat missing check as essentially OK */
                         log_debug_errno(r, "Checking was requested for %s, but fsck.%s does not exist: %m", what, fstype);
                         return 0;
-                } else if (r < 0) {
-                        log_warning_errno(r, "Checking was requested for %s, but fsck.%s cannot be used: %m", what, fstype);
-                        return r;
-                }
+                } else if (r < 0)
+                        return log_warning_errno(r, "Checking was requested for %s, but fsck.%s cannot be used: %m", what, fstype);
         }
 
         if (streq(where, "/")) {