irda: Fix netlink error path return value

Fix an incorrect return value check of genlmsg_put() in irda_nl_get_mode().
genlmsg_put() does not use ERR_PTR() to encode return values, it just
returns NULL on error.
Signed-off-by: NJulius Volz <juliusv@google.com>
Signed-off-by: NSamuel Ortiz <samuel@sortiz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/irda/irnetlink.c

@@ -101,8 +101,8 @@ static int irda_nl_get_mode(struct sk_buff *skb, struct genl_info *info)
 
 	hdr = genlmsg_put(msg, info->snd_pid, info->snd_seq,
 			  &irda_nl_family, 0,  IRDA_NL_CMD_GET_MODE);
-	if (IS_ERR(hdr)) {
-		ret = PTR_ERR(hdr);
+	if (hdr == NULL) {
+		ret = -EMSGSIZE;
 		goto err_out;
 	}