ath5k: remove ah_mac_revision

it's not used, and we have ah_mac_srev.

Signed-off-by: Bruno Randolf <br1@einfach.org>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/ath5k.h

@@ -1047,7 +1047,6 @@ struct ath5k_hw {
 	u32			ah_phy;
 	u32			ah_mac_srev;
 	u16			ah_mac_version;
-	u16			ah_mac_revision;
 	u16			ah_phy_revision;
 	u16			ah_radio_5ghz_revision;
 	u16			ah_radio_2ghz_revision;

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

@@ -148,7 +148,6 @@ int ath5k_hw_attach(struct ath5k_softc *sc)
 	/* Get MAC, PHY and RADIO revisions */
 	ah->ah_mac_srev = srev;
 	ah->ah_mac_version = AR5K_REG_MS(srev, AR5K_SREV_VER);
-	ah->ah_mac_revision = AR5K_REG_MS(srev, AR5K_SREV_REV);
 	ah->ah_phy_revision = ath5k_hw_reg_read(ah, AR5K_PHY_CHIP_ID) &
 			0xffffffff;
 	ah->ah_radio_5ghz_revision = ath5k_hw_radio_revision(ah,