iwlegacy: 4965-mac: mark expected switch fall-through

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/intel/iwlegacy/4965-mac.c

@@ -559,7 +559,7 @@ il4965_translate_rx_status(struct il_priv *il, u32 decrypt_in)
 			decrypt_out |= RX_RES_STATUS_BAD_KEY_TTAK;
 			break;
 		}
-		/* fall through if TTAK OK */
+		/* fall through - if TTAK OK */
 	default:
 		if (!(decrypt_in & RX_MPDU_RES_STATUS_ICV_OK))
 			decrypt_out |= RX_RES_STATUS_BAD_ICV_MIC;