staging: rtl8723bs: Remove comparison to NULL

Remove comparison to NULL in drivers/staging/rtl8723bs/core/rtw_ap.c:1449.
Issue found by checkpatch.pl

Signed-off-by: Wambui Karuga <wambui.karugax@gmail.com>
Link: https://lore.kernel.org/r/20191010132058.20887-1-wambui.karugax@gmail.com


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