cgroup-util: rename cg_get_xattr_malloc -> cg_get_xattr

This is not a trivial wrapper around user-created-buffer-based
syscall, so do not use _malloc suffix. Most of our functions
return an internally allocated buffer and this one's not special.

src/basic/cgroup-util.c

@@ -592,7 +592,7 @@ int cg_set_xattr(const char *path, const char *name, const void *value, size_t s
         return RET_NERRNO(setxattr(fs, name, value, size, flags));
 }
 
-int cg_get_xattr_malloc(const char *path, const char *name, char **ret, size_t *ret_size) {
+int cg_get_xattr(const char *path, const char *name, char **ret, size_t *ret_size) {
         _cleanup_free_ char *fs = NULL;
         int r;