Btrfs: only check delayed ref usage in should_end_transaction

We were only doing btrfs_check_space_for_delayed_refs() if the metadata
space was full, ie we couldn't allocate chunks.  This assumes we'll be
able to allocate chunks during transaction commit, but since nothing
does a LIMIT flush during the transaction commit this won't actually
happen unless we happen to run shy of actual space.  We already take
into account a full fs in btrfs_check_space_for_delayed_refs() so just
kill this extra check to make sure we're ending the transaction when we
need to.
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/transaction.c

@@ -797,8 +797,7 @@ static int should_end_transaction(struct btrfs_trans_handle *trans)
 {
 	struct btrfs_fs_info *fs_info = trans->fs_info;
 
-	if (fs_info->global_block_rsv.space_info->full &&
-	    btrfs_check_space_for_delayed_refs(trans, fs_info))
+	if (btrfs_check_space_for_delayed_refs(trans, fs_info))
 		return 1;
 
 	return !!btrfs_block_rsv_check(&fs_info->global_block_rsv, 5);