ath10k: prevent hif_stop being called twice

Recently there was a bug discovered that involved
hif_stop() being called twice that ended up with a
double free_irq() call but it only manifested with
multiple MSI interrupts mapping.

Catch this kind of a problem early in driver
regardless of interrupt mapping.
Signed-off-by: Michal Kazior <michal.kazior@tieto.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/pci.c

@@ -1272,6 +1272,9 @@ static void ath10k_pci_hif_stop(struct ath10k *ar)
 
 	ath10k_dbg(ATH10K_DBG_BOOT, "boot hif stop\n");
 
+	if (WARN_ON(!ar_pci->started))
+		return;
+
 	ret = ath10k_ce_disable_interrupts(ar);
 	if (ret)
 		ath10k_warn("failed to disable CE interrupts: %d\n", ret);