carl9170: devres ar->survey_info

driver keeps the same survey_info struct for its lifetime around.
This is used because while firmware does help by providing accounting
information of the current channel, it doesn't keep track on the
remaining channels.
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/9b9a059b384f49587f4384ba47f01d3fb2115b22.1646250537.git.chunkeey@gmail.com

drivers/net/wireless/ath/carl9170/main.c

@@ -1916,7 +1916,8 @@ static int carl9170_parse_eeprom(struct ar9170 *ar)
 	if (!bands)
 		return -EINVAL;
 
-	ar->survey = kcalloc(chans, sizeof(struct survey_info), GFP_KERNEL);
+	ar->survey = devm_kcalloc(&ar->udev->dev, chans,
+				  sizeof(struct survey_info), GFP_KERNEL);
 	if (!ar->survey)
 		return -ENOMEM;
 	ar->num_channels = chans;
@@ -2046,9 +2047,6 @@ void carl9170_free(struct ar9170 *ar)
 	kfree_skb(ar->rx_failover);
 	ar->rx_failover = NULL;
 
-	kfree(ar->survey);
-	ar->survey = NULL;
-
 	mutex_destroy(&ar->mutex);
 
 	ieee80211_free_hw(ar->hw);