hv_netvsc: replace divide with mask when computing padding

Packet alignment is always a power of 2 therefore modulus can
be replaced with a faster and operation
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/hyperv/netvsc.c

@@ -712,11 +712,12 @@ static u32 netvsc_copy_to_send_buf(struct netvsc_device *net_device,
 	int i;
 	u32 msg_size = 0;
 	u32 padding = 0;
-	u32 remain = packet->total_data_buflen % net_device->pkt_align;
 	u32 page_count = packet->cp_partial ? packet->rmsg_pgcnt :
 		packet->page_buf_cnt;
+	u32 remain;
 
 	/* Add padding */
+	remain = packet->total_data_buflen & (net_device->pkt_align - 1);
 	if (skb->xmit_more && remain && !packet->cp_partial) {
 		padding = net_device->pkt_align - remain;
 		rndis_msg->msg_len += padding;