link_path_walk: handle get_link() returning ERR_PTR() immediately

If we get ERR_PTR() from get_link(), we are guaranteed to get err != 0
when we break out of do-while, so we are going to hit if (err) return err;
shortly after it.  Pull that into the if (IS_ERR(s)) body.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namei.c b/fs/namei.c
index d729ef7..9937470 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1792,7 +1792,9 @@
 
 				if (unlikely(IS_ERR(s))) {
 					err = PTR_ERR(s);
-					break;
+					current->link_count--;
+					nd->depth--;
+					return err;
 				}
 				err = 0;
 				if (likely(s)) {