ath5k: shifting the wrong variable for AR5K_AR5210

In the original code we shift "AR5K_PHY(256) >> 28" which is zero but
the intent was to shift the return value of ath5k_hw_reg_read() like we
do a couple lines later.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -110,7 +110,7 @@ ath5k_hw_radio_revision(struct ath5k_hw *ah, enum ieee80211_band band)
 		ath5k_hw_reg_write(ah, 0x00010000, AR5K_PHY(0x20));
 
 	if (ah->ah_version == AR5K_AR5210) {
-		srev = ath5k_hw_reg_read(ah, AR5K_PHY(256) >> 28) & 0xf;
+		srev = (ath5k_hw_reg_read(ah, AR5K_PHY(256)) >> 28) & 0xf;
 		ret = (u16)ath5k_hw_bitswap(srev, 4) + 1;
 	} else {
 		srev = (ath5k_hw_reg_read(ah, AR5K_PHY(0x100)) >> 24) & 0xff;