ath6kl: Mark expected switch fall-through

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

Addresses-Coverity-ID: 201383 ("Missing break in switch")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Steve deRosier <derosier@cal-sierra.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath6kl/main.c

@@ -389,6 +389,7 @@ void ath6kl_connect_ap_mode_bss(struct ath6kl_vif *vif, u16 channel)
 		if (!ik->valid || ik->key_type != WAPI_CRYPT)
 			break;
 		/* for WAPI, we need to set the delayed group key, continue: */
+		/* fall through */
 	case WPA_PSK_AUTH:
 	case WPA2_PSK_AUTH:
 	case (WPA_PSK_AUTH | WPA2_PSK_AUTH):