Replace usb_control_msg() with the new usb_control_msg_recv() and
usb_control_msg_send() API of USB Core in usbctrl_vendorreq().
Remove no more needed variables. Move out of an if-else block
some code that it is no more dependent on status < 0. Remove
redundant code depending on status > 0 or status == len.
Suggested-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>