Btrfs: Don't wait on tree block writeback before freeing them anymore

This isn't required anymore because we don't reallocate blocks that
have already been written in this transaction.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 3e1f21c..5632ea7 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -383,9 +383,11 @@
 	struct btrfs_csum_item *item;
 	struct btrfs_path *path = NULL;
 	u32 csum;
+
 	if (btrfs_test_opt(root, NODATASUM) ||
 	    btrfs_test_flag(inode, NODATASUM))
 		return 0;
+
 	mutex_lock(&root->fs_info->fs_mutex);
 	path = btrfs_alloc_path();
 	item = btrfs_lookup_csum(NULL, root, path, inode->i_ino, start, 0);