USB: serial: mxuport: drop short control-transfer check

There's no need to check for short control transfers when sending data
so remove the redundant sanity check.

Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>

drivers/usb/serial/mxuport.c

···
 		return status;
 	}
 
-	if (status != size) {
-		dev_err(&serial->interface->dev,
-			"%s - short write (%d / %zd)\n",
-			__func__, status, size);
-		return -EIO;
-	}
-
 	return 0;
 }