staging: wlan-ng: Fixed incorrect type warning in p80211netdev.c

This change fixes a sparse warning "incorrect type in argument 1
(different address spaces)".
Reviewed-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Pritthijit Nath <pritthijit.nath@icloud.com>
Link: https://lore.kernel.org/r/20210217154255.112115-1-pritthijit.nath@icloud.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wlan-ng/p80211netdev.c

@@ -569,7 +569,7 @@ static int p80211knetdev_do_ioctl(struct net_device *dev,
 		goto bail;
 	}
 
-	msgbuf = memdup_user(req->data, req->len);
+	msgbuf = memdup_user((void __user *)req->data, req->len);
 	if (IS_ERR(msgbuf)) {
 		result = PTR_ERR(msgbuf);
 		goto bail;