Btrfs: reset intwrite on transaction abort

If we abort a transaction in the middle of a commit we weren't undoing the
intwrite locking.  This patch fixes that problem.

Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

fs/btrfs/transaction.c

@@ -1552,6 +1552,8 @@ static void cleanup_transaction(struct btrfs_trans_handle *trans,
 		root->fs_info->running_transaction = NULL;
 	spin_unlock(&root->fs_info->trans_lock);
 
+	if (trans->type & __TRANS_FREEZABLE)
+		sb_end_intwrite(root->fs_info->sb);
 	put_transaction(cur_trans);
 	put_transaction(cur_trans);