PM: domains: Simplify the calculation of variables

Fix the following coccicheck warnings:

./drivers/base/power/domain.c:938:31-33: WARNING !A || A && B is
equivalent to !A || B.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Suggested-by: Jiapeng Zhong <oswb@linux.alibaba.com>
Signed-off-by: Abaci Team <abaci-bugfix@linux.alibaba.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>