staging: rtl8188eu: rename HalSetBrateCfg() - style

Rename HalSetBrateCfg() to avoid CamelCase.
HalSetBrateCfg -> hal_set_brate_cfg

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>