ath5k: remove redundant pointer rf

Pointer rf is being assigned but is never used hence it is redundant
and can be removed.

Cleans up two clang warnings:
warning: variable 'rf' set but not used [-Wunused-but-set-variable]
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath5k/phy.c

@@ -483,7 +483,6 @@ static u32
 ath5k_hw_rf_gainf_corr(struct ath5k_hw *ah)
 {
 	u32 mix, step;
-	u32 *rf;
 	const struct ath5k_gain_opt *go;
 	const struct ath5k_gain_opt_step *g_step;
 	const struct ath5k_rf_reg *rf_regs;
@@ -502,7 +501,6 @@ ath5k_hw_rf_gainf_corr(struct ath5k_hw *ah)
 	if (ah->ah_rf_banks == NULL)
 		return 0;
 
-	rf = ah->ah_rf_banks;
 	ah->ah_gain.g_f_corr = 0;
 
 	/* No VGA (Variable Gain Amplifier) override, skip */
@@ -549,13 +547,10 @@ ath5k_hw_rf_check_gainf_readback(struct ath5k_hw *ah)
 {
 	const struct ath5k_rf_reg *rf_regs;
 	u32 step, mix_ovr, level[4];
-	u32 *rf;
 
 	if (ah->ah_rf_banks == NULL)
 		return false;
 
-	rf = ah->ah_rf_banks;
-
 	if (ah->ah_radio == AR5K_RF5111) {
 
 		rf_regs = rf_regs_5111;