do_fchownat(): unspaghettify a bit...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/open.c

@@ -810,30 +810,26 @@ int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
 	struct path path;
 	int error;
 	int lookup_flags;
-	struct filename *name;
 
 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
 		return -EINVAL;
 
 	lookup_flags = (flag & AT_SYMLINK_NOFOLLOW) ? 0 : LOOKUP_FOLLOW;
-	name = getname_uflags(filename, flag);
+	CLASS(filename_uflags, name)(filename, flag);
 retry:
 	error = filename_lookup(dfd, name, lookup_flags, &path, NULL);
-	if (error)
-		goto out;
-	error = mnt_want_write(path.mnt);
-	if (error)
-		goto out_release;
-	error = chown_common(&path, user, group);
-	mnt_drop_write(path.mnt);
-out_release:
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
+	if (!error) {
+		error = mnt_want_write(path.mnt);
+		if (!error) {
+			error = chown_common(&path, user, group);
+			mnt_drop_write(path.mnt);
+		}
+		path_put(&path);
+		if (retry_estale(error, lookup_flags)) {
+			lookup_flags |= LOOKUP_REVAL;
+			goto retry;
+		}
 	}
-out:
-	putname(name);
 	return error;
 }