staging: rtl8192u: make in r819xU_firmware.c some local functions static

Make some local functions static (firmware_init_param, fw_download_code,
CPUcheck_maincodeok_turnonCPU and CPUcheck_firmware_ready) and fix
coding style in these function declarations when It is necessary.

Fixed the following sparse warnings in r819xU_firmware.c

  CHECK   drivers/staging/rtl8192u/r819xU_firmware.c
drivers/staging/rtl8192u/r819xU_firmware.c:20:6: warning: symbol 'firmware_init_param' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware.c:32:6: warning: symbol 'fw_download_code' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware.c:159:6: warning: symbol 'CPUcheck_maincodeok_turnonCPU' was not declared. Should it be static?
drivers/staging/rtl8192u/r819xU_firmware.c:208:6: warning: symbol 'CPUcheck_firmware_ready' was not declared. Should it be static?

Signed-off-by: Ana Rey <anarey@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>