Fixes the following W=1 kernel build warning(s):

 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_wifi_idle_process’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:1631:40: warning: variable ‘bt_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:1631:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_sco’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:2767:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_hid’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:2810:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_a2dp’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:2855:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_a2dp_pan_hs’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:2929:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_pan_edr’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:2976:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_pan_hs’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3028:22: warning: variable ‘wifi_rssi_state1’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3028:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_pan_edr_a2dp’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3066:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_pan_edr_hid’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3121:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_hid_a2dp_pan_edr’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3185:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c: In function ‘btc8723b2ant_action_hid_a2dp’:
 drivers/net/wireless/realtek/rtlwifi/btcoexist/halbtc8723b2ant.c:3244:5: warning: variable ‘wifi_rssi_state’ set but not used [-Wunused-but-set-variable]

Cc: Ping-Ke Shih <pkshih@realtek.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201102112410.1049272-26-lee.jones@linaro.org