staging: rtl8723bs: Fix camel-case in 'struct rt_firmware'.

Change the members of 'struct rt_firmware' to be snake case instead
of camel-case, per the kernel coding style guide.

Signed-off-by: Quytelda Kahja <quytelda@tamalin.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>