nexthop: Unlink nexthop group entry in error path

In case of error, remove the nexthop group entry from the list to which
it was previously added.

Fixes: 430a0491 ("nexthop: Add support for nexthop groups")
Signed-off-by: NIdo Schimmel <idosch@nvidia.com>
Reviewed-by: NPetr Machata <petrm@nvidia.com>
Reviewed-by: NDavid Ahern <dsahern@kernel.org>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

net/ipv4/nexthop.c

@@ -1459,8 +1459,10 @@ static struct nexthop *nexthop_create_group(struct net *net,
 	return nh;
 
 out_no_nh:
-	for (i--; i >= 0; --i)
+	for (i--; i >= 0; --i) {
+		list_del(&nhg->nh_entries[i].nh_list);
 		nexthop_put(nhg->nh_entries[i].nh);
+	}
 
 	kfree(nhg->spare);
 	kfree(nhg);