ath11k: avoid while loop in ring selection of tx completion interrupt

Currently while loop is used to find the tx completion ring number and
it is not required since the tx ring mask and the group id can be combined
to directly fetch the ring number. Hence remove the while loop
and directly get the ring number from tx mask and group id.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2
Co-developed-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: P Praneesh <ppranees@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1630560820-21905-11-git-send-email-ppranees@codeaurora.org

drivers/net/wireless/ath/ath11k/dp.c

@@ -771,13 +771,12 @@ int ath11k_dp_service_srng(struct ath11k_base *ab,
 	const struct ath11k_hw_hal_params *hal_params;
 	int grp_id = irq_grp->grp_id;
 	int work_done = 0;
-	int i = 0, j;
+	int i, j;
 	int tot_work_done = 0;
 
-	while (ab->hw_params.ring_mask->tx[grp_id] >> i) {
-		if (ab->hw_params.ring_mask->tx[grp_id] & BIT(i))
-			ath11k_dp_tx_completion_handler(ab, i);
-		i++;
+	if (ab->hw_params.ring_mask->tx[grp_id]) {
+		i = __fls(ab->hw_params.ring_mask->tx[grp_id]);
+		ath11k_dp_tx_completion_handler(ab, i);
 	}
 
 	if (ab->hw_params.ring_mask->rx_err[grp_id]) {