Staging: rtl8712 : wifi.h: Fixed Macro argument reuse

CHECK: Macro argument reuse 'pframe' - possible side-effects?

Convert get_tofr_ds macro to inline functions to fix checkpatch check

Signed-off-by: Jaya Durga <rjdurga@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>