ath9k: initialize hw prior to debugfs

debugfs uses the hardware for several debugfs files as such the
hardware must be initialized and available prior to its usage. The
same applies to when we free the hw structs -- free debufs file
entries prior to free'ing the hardware.

Reported-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/hw.c

@@ -999,6 +999,8 @@ int ath9k_hw_init(struct ath_hw *ah)
 
 	ath9k_init_nfcal_hist_buffer(ah);
 
+	common->state = ATH_HW_INITIALIZED;
+
 	return 0;
 }
 
@@ -1239,11 +1241,18 @@ const char *ath9k_hw_probe(u16 vendorid, u16 devid)
 
 void ath9k_hw_detach(struct ath_hw *ah)
 {
+	struct ath_common *common = ath9k_hw_common(ah);
+
+	if (common->state <= ATH_HW_INITIALIZED)
+		goto free_hw;
+
 	if (!AR_SREV_9100(ah))
 		ath9k_hw_ani_disable(ah);
 
-	ath9k_hw_rf_free(ah);
 	ath9k_hw_setpower(ah, ATH9K_PM_FULL_SLEEP);
+
+free_hw:
+	ath9k_hw_rf_free(ah);
 	kfree(ah);
 	ah = NULL;
 }