drivers/net/usb: 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>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/asix.c

@@ -224,10 +224,9 @@ static int asix_write_cmd(struct usbnet *dev, u8 cmd, u16 value, u16 index,
 		   cmd, value, index, size);
 
 	if (data) {
-		buf = kmalloc(size, GFP_KERNEL);
+		buf = kmemdup(data, size, GFP_KERNEL);
 		if (!buf)
 			goto out;
-		memcpy(buf, data, size);
 	}
 
 	err = usb_control_msg(

drivers/net/usb/mcs7830.c

@@ -142,12 +142,10 @@ static int mcs7830_set_reg(struct usbnet *dev, u16 index, u16 size, const void *
 	int ret;
 	void *buffer;
 
-	buffer = kmalloc(size, GFP_NOIO);
+	buffer = kmemdup(data, size, GFP_NOIO);
 	if (buffer == NULL)
 		return -ENOMEM;
 
-	memcpy(buffer, data, size);
-
 	ret = usb_control_msg(xdev, usb_sndctrlpipe(xdev, 0), MCS7830_WR_BREQ,
 			      MCS7830_WR_BMREQ, 0x0000, index, buffer,
 			      size, MCS7830_CTRL_TIMEOUT);