xfs: fix error bailout in xrep_abt_build_new_trees

Dan Carpenter reports:

"Commit 4bdfd7d1 ("xfs: repair free space btrees") from Dec 15,
2023 (linux-next), leads to the following Smatch static checker
warning:

        fs/xfs/scrub/alloc_repair.c:781 xrep_abt_build_new_trees()
        warn: missing unwind goto?"

That's a bug, so let's fix it.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 4bdfd7d1 ("xfs: repair free space btrees")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/scrub/alloc_repair.c

@@ -778,7 +778,7 @@ xrep_abt_build_new_trees(
 
 	error = xrep_bnobt_sort_records(ra);
 	if (error)
-		return error;
+		goto err_levels;
 
 	/* Load the free space by block number tree. */
 	ra->array_cur = XFARRAY_CURSOR_INIT;