ath5k: fix memory leak when fewer than N_PD_CURVES are in use

We would free the proper number of curves, but in the wrong
slots, due to a missing level of indirection through
the pdgain_idx table.

It's simpler just to try to free all four slots, so do that.

Cc: stable@kernel.org
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -691,15 +691,13 @@ ath5k_eeprom_free_pcal_info(struct ath5k_hw *ah, int mode)
 		if (!chinfo[pier].pd_curves)
 			continue;
 
-		for (pdg = 0; pdg < ee->ee_pd_gains[mode]; pdg++) {
+		for (pdg = 0; pdg < AR5K_EEPROM_N_PD_CURVES; pdg++) {
 			struct ath5k_pdgain_info *pd =
 					&chinfo[pier].pd_curves[pdg];
 
-			if (pd != NULL) {
 			kfree(pd->pd_step);
 			kfree(pd->pd_pwr);
 		}
-		}
 
 		kfree(chinfo[pier].pd_curves);
 	}