staging: comedi: usbduxfast: tidy up firmwareUpload()

Rename the CamelCase function and just pass the const struct
firmware * directly instead of parsing out the data and size.

Rename the CamelCasae local val 'fwBuf'.

Use goto to provide a common exit path that frees the local
buffer for the firmware when an error is encountered.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>