locks: update comments that refer to inode->i_flock

Signed-off-by: Jeff Layton <jlayton@primarydata.com>

fs/locks.c

@@ -2212,7 +2212,7 @@ again:
 	 */
 	/*
 	 * we need that spin_lock here - it prevents reordering between
-	 * update of inode->i_flock and check for it done in close().
+	 * update of i_flctx->flc_posix and check for it done in close().
 	 * rcu_read_lock() wouldn't do.
 	 */
 	spin_lock(&current->files->file_lock);