ath5k: cleanup channel to eprom_mode function

Stop returning negative values from ath5k_eeprom_mode_from_channel.
Yell loudly about that case in that function instead and return the
default/zero/mode A. This cleans up the callers, but needs to pass ah
down to ath5k_eeprom_mode_from_channel for ATH5K_WARN. For that
purpose we also need the declaration to be moved to ath5k.h.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -1779,7 +1779,8 @@ ath5k_eeprom_detach(struct ath5k_hw *ah)
 }
 
 int
-ath5k_eeprom_mode_from_channel(struct ieee80211_channel *channel)
+ath5k_eeprom_mode_from_channel(struct ath5k_hw *ah,
+		struct ieee80211_channel *channel)
 {
 	switch (channel->hw_value) {
 	case AR5K_MODE_11A:
@@ -1789,6 +1790,7 @@ ath5k_eeprom_mode_from_channel(struct ieee80211_channel *channel)
 	case AR5K_MODE_11B:
 		return AR5K_EEPROM_MODE_11B;
 	default:
-		return -1;
+		ATH5K_WARN(ah, "channel is not A/B/G!");
+		return AR5K_EEPROM_MODE_11A;
 	}
 }