rtlwifi: rtl8821ae: fix comparison to bool warning in phy.c

Fixes coccicheck warning:

drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:1816:5-13: WARNING: Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:1825:5-13: WARNING: Comparison to bool
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:1839:5-13: WARNING: Comparison to bool

Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200918102505.16036-6-zhengbin13@huawei.com