wifi: mac80211: mlme: release deflink channel in error case

In the prep_channel error case we didn't release the deflink
channel leaving it to be left around. Fix that.

Change-Id: If0dfd748125ec46a31fc6045a480dc28e03723d2
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/mlme.c

@@ -6509,6 +6509,7 @@ static int ieee80211_prep_connection(struct ieee80211_sub_if_data *sdata,
 	return 0;
 
 out_err:
+	ieee80211_link_release_channel(&sdata->deflink);
 	ieee80211_vif_set_links(sdata, 0);
 	return err;
 }