ath10k: plug memory leak in wmi mgmt tx worker

sk_buff was not freed in some cases. The patch
unifies the msdu freeing.

Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath10k/wmi.c b/drivers/net/wireless/ath/ath10k/wmi.c
index a796d0b..8db9db2 100644
--- a/drivers/net/wireless/ath/ath10k/wmi.c
+++ b/drivers/net/wireless/ath/ath10k/wmi.c
@@ -674,10 +674,8 @@
 
 	/* Send the management frame buffer to the target */
 	ret = ath10k_wmi_cmd_send(ar, wmi_skb, ar->wmi.cmd->mgmt_tx_cmdid);
-	if (ret) {
-		dev_kfree_skb_any(skb);
+	if (ret)
 		return ret;
-	}
 
 	/* TODO: report tx status to mac80211 - temporary just ACK */
 	info->flags |= IEEE80211_TX_STAT_ACK;