USB: usbtest.c: length, sglen and vary are unsigned, so cannot be negative

length, sglen and vary are unsigned, so cannot be negative

see
vi drivers/usb/misc/usbtest.c +18
struct usbtest_param {
...
        unsigned                iterations;
        unsigned                length;
        unsigned                vary;
        unsigned                sglen;
...
};
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/misc/usbtest.c

@@ -1561,8 +1561,7 @@ usbtest_ioctl (struct usb_interface *intf, unsigned int code, void *buf)
 	if (code != USBTEST_REQUEST)
 		return -EOPNOTSUPP;
 
-	if (param->iterations <= 0 || param->length < 0
-			|| param->sglen < 0 || param->vary < 0)
+	if (param->iterations <= 0)
 		return -EINVAL;
 
 	if (mutex_lock_interruptible(&dev->lock))