nfc: Fix portid type in urelease_work

portid is an unsigned integer. Fix urelease_work to
match all other portid user in the kernel.
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/nfc/netlink.c

@@ -1584,7 +1584,7 @@ static const struct genl_ops nfc_genl_ops[] = {
 
 struct urelease_work {
 	struct	work_struct w;
-	int	portid;
+	u32	portid;
 };
 
 static void nfc_urelease_event_work(struct work_struct *work)