staging: rtl8723bs: remove redundant null check on pregpriv

The null check on &padapter->registrypriv is redundant since registrypriv
is a struct inside padapter and can never be null, so the check is always
true.  we may remove it.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
CC: devel@driverdev.osuosl.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>