ext4: remove unused value

This fixes build error.

Change-Id: Ic0d93db329b770913314c212a13564ed96cfecf3
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 3491d48..f6606f3 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1337,7 +1337,7 @@
 				   buffer */
 	int num = 0;
 	ext4_lblk_t  nblocks;
-	int i, namelen, retval;
+	int i, namelen;
 
 	*res_dir = NULL;
 	sb = dir->i_sb;