ath11k: Remove unnecessary data sync to cpu on monitor buffer

Monitor ring Rx buffer is not really modified between dma map
and unmap. So remove the unnecssary data sync before dma unmap.
This does not fix any visible issue, found in code review.

Compile tested only.
Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1602744454-22969-1-git-send-email-vthiagar@codeaurora.org

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

@@ -2856,10 +2856,6 @@ static int ath11k_dp_rx_reap_mon_status_ring(struct ath11k_base *ab, int mac_id,
 
 			rxcb = ATH11K_SKB_RXCB(skb);
 
-			dma_sync_single_for_cpu(ab->dev, rxcb->paddr,
-						skb->len + skb_tailroom(skb),
-						DMA_FROM_DEVICE);
-
 			dma_unmap_single(ab->dev, rxcb->paddr,
 					 skb->len + skb_tailroom(skb),
 					 DMA_BIDIRECTIONAL);