staging: comedi: usbduxfast: consolidate the firmware upload
staging: comedi: usbduxfast: consolidate the firmware upload

Absorb the usbduxfastsub_stop(), usbduxfastsub_upload(), and
usbduxfastsub_start() functions into usbduxfast_upload_firmware().

Each of them just do a usb_control_msg() to the device and output
an error message if it fails. A similar message is also output by
usbduxfast_upload_firmware() so the extra messages are redundant.

We can also share the malloc'ed local buffer needed for the
usb_control_msg().

Signed-off-by: H Hartley Sweeten <382ff55d8e07d1082d179e669636cd1552da4f36@visionengravers.com>
Cc: Ian Abbott <9e6ba6483b6a3e14d61f7c987e72ecb5b46122d6@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs