net: team: fix incorrect maxattr

The maxattr should be the latest attr value, i.e. array size - 1,
not total array size.

Reported-by: syzbot+ecd7e07b4be038658c9f@syzkaller.appspotmail.com
Fixes: 948dbafc ("net: team: use policy generated by YAML spec")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240409092812.3999785-1-liuhangbin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/team/team_core.c

@@ -2808,7 +2808,7 @@ static const struct genl_multicast_group team_nl_mcgrps[] = {
 static struct genl_family team_nl_family __ro_after_init = {
 	.name		= TEAM_GENL_NAME,
 	.version	= TEAM_GENL_VERSION,
-	.maxattr	= ARRAY_SIZE(team_nl_policy),
+	.maxattr	= ARRAY_SIZE(team_nl_policy) - 1,
 	.policy = team_nl_policy,
 	.netnsok	= true,
 	.module		= THIS_MODULE,