staging: rtl8723bs: Simplify boolean expression

Simplify expression that it's inverting a boolean value.
Issue found by Coccinelle.

Signed-off-by: Javier F. Arias <jarias.linux@gmail.com>
Link: https://lore.kernel.org/r/9799bed4370f8cc1bd6a1735721fcd91fac30e09.1572640293.git.jarias.linux@gmail.com


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