Staging: rtl8192su: refactored FirmwareDownload92S

added a new function: FirmwareRequest92S

This function(instead of FirmwareDownload92S) is now responsible for
requesting the firmware.

FirmwareDownload92S is now easier to read, smaller and follows kernel
coding style.

plus cosmetics.

Signed-off-by: Florian Schilhabel <florian.c.schilhabel@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>