btrfs: Remove block_rsv parameter from btrfs_drop_snapshot

It's no longer used following 30d40577e322 ("btrfs: reloc: Also queue
orphan reloc tree for cleanup to avoid BUG_ON()"), so just remove it.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 096c0aa..5939bca 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -2427,9 +2427,9 @@ int btrfs_clean_one_deleted_snapshot(struct btrfs_root *root)
 
 	if (btrfs_header_backref_rev(root->node) <
 			BTRFS_MIXED_BACKREF_REV)
-		ret = btrfs_drop_snapshot(root, NULL, 0, 0);
+		ret = btrfs_drop_snapshot(root, 0, 0);
 	else
-		ret = btrfs_drop_snapshot(root, NULL, 1, 0);
+		ret = btrfs_drop_snapshot(root, 1, 0);
 
 	return (ret < 0) ? 0 : 1;
 }