[media] media: usb: cpia2: Use kmemdup instead of kmalloc and memcpy

When some other buffer is immediately copied into allocated region.
Replace calls to kmalloc followed by a memcpy with a direct
call to kmemdup.
Signed-off-by: NShyam Saini <mayhs11saini@gmail.com>
Signed-off-by: NHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/cpia2/cpia2_usb.c

@@ -547,12 +547,10 @@ static int write_packet(struct usb_device *udev,
 	if (!registers || size <= 0)
 		return -EINVAL;
 
-	buf = kmalloc(size, GFP_KERNEL);
+	buf = kmemdup(registers, size, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
-	memcpy(buf, registers, size);
-
 	ret = usb_control_msg(udev,
 			       usb_sndctrlpipe(udev, 0),
 			       request,