link_path_walk: end of nd->depth massage

get rid of orig_depth - we only use it on error exit to tell whether
to stop doing put_link() when depth reaches 0 (call from path_init())
or when it reaches 1 (call from trailing_symlink()).  However, in
the latter case the caller would immediately follow with one more
put_link().  Just keep doing it until the depth reaches zero (and
simplify trailing_symlink() as the result).
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/namei.c

@@ -1759,7 +1759,6 @@ static inline u64 hash_name(const char *name)
 static int link_path_walk(const char *name, struct nameidata *nd)
 {
 	int err;
-	int orig_depth = nd->depth;
 
 	while (*name=='/')
 		name++;
@@ -1868,7 +1867,7 @@ static int link_path_walk(const char *name, struct nameidata *nd)
 	}
 	terminate_walk(nd);
 Err:
-	while (unlikely(nd->depth > orig_depth))
+	while (unlikely(nd->depth))
 		put_link(nd);
 	return err;
 OK:
@@ -2017,10 +2016,7 @@ static int trailing_symlink(struct nameidata *nd)
 	}
 	nd->inode = nd->path.dentry->d_inode;
 	nd->stack[0].name = NULL;
-	error = link_path_walk(s, nd);
-	if (unlikely(error))
-		put_link(nd);
-	return error;
+	return link_path_walk(s, nd);
 }
 
 static inline int lookup_last(struct nameidata *nd)