cgroup/cpuset: Fix retval in update_cpumask()

The update_cpumask(), checks for newly requested cpumask by calling
validate_change(), which returns an error on passing an invalid set
of cpu(s). Independent of the error returned, update_cpumask() always
returns zero, suppressing the error and returning success to the user
on writing an invalid cpu range for a cpuset. Fix it by returning
retval instead, which is returned by validate_change().

Fixes: 99fe36b ("cgroup/cpuset: Improve temporary cpumasks handling")
Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org # v6.6+
Signed-off-by: Tejun Heo <tj@kernel.org>

Author: kamalesh-babulal

kernel/cgroup/cpuset.c

@@ -2562,7 +2562,7 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
 		update_partition_sd_lb(cs, old_prs);
 out_free:
 	free_cpumasks(NULL, &tmp);
-	return 0;
+	return retval;
 }
 
 /**