networking: introduce and use skb_put_data()

A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/bluetooth/bfusb.c b/drivers/bluetooth/bfusb.c
index 3bf4ec6..ab090a3 100644
--- a/drivers/bluetooth/bfusb.c
+++ b/drivers/bluetooth/bfusb.c
@@ -335,7 +335,7 @@ static inline int bfusb_recv_block(struct bfusb_data *data, int hdr, unsigned ch
 	}
 
 	if (len > 0)
-		memcpy(skb_put(data->reassembly, len), buf, len);
+		skb_put_data(data->reassembly, buf, len);
 
 	if (hdr & 0x08) {
 		hci_recv_frame(data->hdev, data->reassembly);
@@ -505,7 +505,7 @@ static int bfusb_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 		buf[1] = 0x00;
 		buf[2] = (size == BFUSB_MAX_BLOCK_SIZE) ? 0 : size;
 
-		memcpy(skb_put(nskb, 3), buf, 3);
+		skb_put_data(nskb, buf, 3);
 		skb_copy_from_linear_data_offset(skb, sent, skb_put(nskb, size), size);
 
 		sent  += size;
@@ -516,7 +516,7 @@ static int bfusb_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
 	if ((nskb->len % data->bulk_pkt_size) == 0) {
 		buf[0] = 0xdd;
 		buf[1] = 0x00;
-		memcpy(skb_put(nskb, 2), buf, 2);
+		skb_put_data(nskb, buf, 2);
 	}
 
 	read_lock(&data->lock);