net/hsr: Check skb_put_padto() return value

commit 414e7d76 upstream.

skb_put_padto() will free the sk_buff passed as reference in case of
errors, but we still need to check its return value and decide what to
do.

Detected by CoverityScan, CID#1416688 ("CHECKED_RETURN")

Fixes: ee1c2797 ("net/hsr: Added support for HSR v1")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/hsr/hsr_device.c

@@ -315,7 +315,8 @@ static void send_hsr_supervision_frame(struct hsr_port *master,
 	hsr_sp = (typeof(hsr_sp)) skb_put(skb, sizeof(struct hsr_sup_payload));
 	ether_addr_copy(hsr_sp->MacAddressA, master->dev->dev_addr);
 
-	skb_put_padto(skb, ETH_ZLEN + HSR_HLEN);
+	if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN))
+		return;
 
 	hsr_forward_skb(skb, master);
 	return;