drivers/net/wireless/libertas: Use kmemdup

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_usb.c

@@ -613,16 +613,14 @@ static void if_usb_receive_fwload(struct urb *urb)
 		return;
 	}
 
-	syncfwheader = kmalloc(sizeof(struct fwsyncheader), GFP_ATOMIC);
+	syncfwheader = kmemdup(skb->data + IPFIELD_ALIGN_OFFSET,
+			       sizeof(struct fwsyncheader), GFP_ATOMIC);
 	if (!syncfwheader) {
 		lbs_deb_usbd(&cardp->udev->dev, "Failure to allocate syncfwheader\n");
 		kfree_skb(skb);
 		return;
 	}
 
-	memcpy(syncfwheader, skb->data + IPFIELD_ALIGN_OFFSET,
-	       sizeof(struct fwsyncheader));
-
 	if (!syncfwheader->cmd) {
 		lbs_deb_usb2(&cardp->udev->dev, "FW received Blk with correct CRC\n");
 		lbs_deb_usb2(&cardp->udev->dev, "FW received Blk seqnum = %d\n",