staging: rtl8712: Remove unnecessary int typecast

This patch gets rid of the following error from checkpatch.pl:
WARNING: Unnecessary typecast of c90 int constant.

Signed-off-by: Solomon Tan <solomonbstoner@protonmail.ch>
Link: https://lore.kernel.org/r/YlxGTMBsLqdOIrpC@ArchDesktop


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>