rtlwifi: rtl8723ae: fix warning comparison to bool

Fix the following coccicheck warning:

drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c:617:14-20: WARNING:
Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c:622:13-19: WARNING:
Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c:627:14-20: WARNING:
Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c:632:13-19: WARNING:
Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8723ae/hw.c:937:5-13: WARNING:
Comparison to bool

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200420042658.18733-1-yanaijie@huawei.com