ath10k: htt_tx: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular case, I replaced "pass through" with
a proper "fall through" comment, which is what GCC is expecting
to find.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

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

@@ -1202,7 +1202,7 @@ static int ath10k_htt_tx_32(struct ath10k_htt *htt,
 	case ATH10K_HW_TXRX_RAW:
 	case ATH10K_HW_TXRX_NATIVE_WIFI:
 		flags0 |= HTT_DATA_TX_DESC_FLAGS0_MAC_HDR_PRESENT;
-		/* pass through */
+		/* fall through */
 	case ATH10K_HW_TXRX_ETHERNET:
 		if (ar->hw_params.continuous_frag_desc) {
 			ext_desc_t = htt->frag_desc.vaddr_desc_32;
@@ -1404,7 +1404,7 @@ static int ath10k_htt_tx_64(struct ath10k_htt *htt,
 	case ATH10K_HW_TXRX_RAW:
 	case ATH10K_HW_TXRX_NATIVE_WIFI:
 		flags0 |= HTT_DATA_TX_DESC_FLAGS0_MAC_HDR_PRESENT;
-		/* pass through */
+		/* fall through */
 	case ATH10K_HW_TXRX_ETHERNET:
 		if (ar->hw_params.continuous_frag_desc) {
 			ext_desc_t = htt->frag_desc.vaddr_desc_64;