Fix compiler warnings

src/cnetz/fsk_demod.c

@@ -379,7 +379,7 @@ got_sync:
 		break;
 	case FSK_SYNC_NEGATIVE:
 		bit = 1 - bit;
-		/* fall through */
+		/* FALLTHRU */
 	case FSK_SYNC_POSITIVE:
 		fsk->rx_buffer[fsk->rx_buffer_count] = bit + '0';
 		if (++fsk->rx_buffer_count == 150) {

src/cnetz/telegramm.c

@@ -454,7 +454,7 @@ int init_telegramm(void)
 
 const char *telegramm2rufnummer(telegramm_t *telegramm)
 {
-	static char rufnummer[9];
+	static char rufnummer[32]; /* make GCC happy (overflow check) */
 
 	sprintf(rufnummer, "%d%d%05d", telegramm->futln_nationalitaet, telegramm->futln_heimat_fuvst_nr, telegramm->futln_rest_nr);
 

src/cnetz/transaction.c

@@ -30,7 +30,7 @@
 
 const char *transaction2rufnummer(transaction_t *trans)
 {
-	static char rufnummer[9];
+	static char rufnummer[32]; /* make GCC happy (overflow check) */
 
 	sprintf(rufnummer, "%d%d%05d", trans->futln_nat, trans->futln_fuvst, trans->futln_rest);