reiserfs: fix dereference of ERR_PTR

reiserfs_iget() returns either NULL or error code in ERR_PTR.  And we
were only checking for NULL, so in case of some other error we will try
to dereference the ERR_PTR(-errno) thinking it to be a valid pointer.
Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/reiserfs/super.c

@@ -288,7 +288,7 @@ static int finish_unfinished(struct super_block *s)
 		pathrelse(&path);
 
 		inode = reiserfs_iget(s, &obj_key);
-		if (!inode) {
+		if (IS_ERR_OR_NULL(inode)) {
 			/*
 			 * the unlink almost completed, it just did not
 			 * manage to remove "save" link and release objectid