staging: wlan-ng: Replace data type declaration with variable of same type in hfa384x_usb.c

sizeof(var) instead of sizeof(struct XXX) is preferred.
Fix it in hfa384x_usb.c file.
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/hfa384x_usb.c

@@ -531,7 +531,7 @@ static void hfa384x_usb_defer(struct work_struct *data)
  */
 void hfa384x_create(struct hfa384x *hw, struct usb_device *usb)
 {
-	memset(hw, 0, sizeof(struct hfa384x));
+	memset(hw, 0, sizeof(*hw));
 	hw->usb = usb;
 
 	/* set up the endpoints */