rtlwifi: rtl8821ae: Remove set but not used variables 'rtstatus','bd'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c: In function rtl8812ae_phy_config_rf_with_headerfile:
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:2079:7: warning: variable rtstatus set but not used [-Wunused-but-set-variable]
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c: In function rtl8821ae_phy_config_rf_with_headerfile:
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:2114:7: warning: variable rtstatus set but not used [-Wunused-but-set-variable]
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c: In function _rtl8812ae_phy_get_txpower_limit:
drivers/net/wireless/realtek/rtlwifi/rtl8821ae/phy.c:2354:6: warning: variable bd set but not used [-Wunused-but-set-variable]

They are not used since commit f1d2b4d3 ("rtlwifi:
rtl818x: Move drivers into new realtek directory")

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>