net: qualcomm: rmnet: Use skb_put_zero() to simplify code

Use skb_put_zero() instead of hand-writing it. This saves a few lines of
code and is more readable.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qualcomm/rmnet/rmnet_map_data.c

@@ -298,7 +298,6 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 {
 	struct rmnet_map_header *map_header;
 	u32 padding, map_datalen;
-	u8 *padbytes;
 
 	map_datalen = skb->len - hdrlen;
 	map_header = (struct rmnet_map_header *)
@@ -323,8 +322,7 @@ struct rmnet_map_header *rmnet_map_add_map_header(struct sk_buff *skb,
 	if (skb_tailroom(skb) < padding)
 		return NULL;
 
-	padbytes = (u8 *)skb_put(skb, padding);
-	memset(padbytes, 0, padding);
+	skb_put_zero(skb, padding);
 
 done:
 	map_header->pkt_len = htons(map_datalen + padding);