staging: r8188eu: remove unnecessary parentheses in core/rtw_pwrctrl.c

Remove unnecessary parentheses in core/rtw_pwrctrl.c reported by
checkpatch.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210809165007.23204-14-straube.linux@gmail.com


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