ath10k: release conf_mutex if vdev_start() fails

I modified Michal's commit c930f744bdb0 ("ath10k: implement channel switching") to return
when vdev_start() fails, but forgot to release conf_mutex.

Found by coccinelle:

>> drivers/net/wireless/ath/ath10k/mac.c:2745:5-11: preceding lock on line 2663

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/wireless/ath/ath10k/mac.c b/drivers/net/wireless/ath/ath10k/mac.c
index 5c5860ef36bd..44b550b2fcfd 100644
--- a/drivers/net/wireless/ath/ath10k/mac.c
+++ b/drivers/net/wireless/ath/ath10k/mac.c
@@ -2785,7 +2785,7 @@ static void ath10k_bss_info_changed(struct ieee80211_hw *hw,
                                 if (ret) {
                                         ath10k_warn("failed to start vdev: %d\n",
                                                     ret);
-                                        return;
+                                        goto exit;
                                 }
 
                                 arvif->is_started = true;
@@ -2866,6 +2866,7 @@ static void ath10k_bss_info_changed(struct ieee80211_hw *hw,
                         ath10k_bss_assoc(hw, vif, info);
         }
 
+exit:
         mutex_unlock(&ar->conf_mutex);
 }