btrfs: make btrfs_clear_delalloc_extent() free delalloc reserve

Currently, this call site in btrfs_clear_delalloc_extent() only converts
the reservation. We are marking it not delalloc, so I don't think it
makes sense to keep the rsv around.  This is a path where we are not
sure to join a transaction, so it leads to incorrect free-ing during
umount.

Helps with the pass rate of generic/269 and generic/475.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -2536,7 +2536,7 @@ void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
 		 */
 		if (bits & EXTENT_CLEAR_META_RESV &&
 		    root != fs_info->tree_root)
-			btrfs_delalloc_release_metadata(inode, len, false);
+			btrfs_delalloc_release_metadata(inode, len, true);
 
 		/* For sanity tests. */
 		if (btrfs_is_testing(fs_info))