db_text: Fix Coverity warning (bad 'switch' fallthrough)

Thanks to Răzvan Crainea for the help!

(cherry picked from commit 6b56ca5)
(cherry picked from commit 8b9307f)

modules/db_text/dbt_lib.c

@@ -537,34 +537,47 @@ int dbt_is_neq_type(db_type_t _t0, db_type_t _t1)
 	// LM_DBG("t0=%d t1=%d!\n", _t0, _t1);
 	if(_t0 == _t1)
 		return 0;
-	switch(_t1)
-	{
-		case DB_INT:
-			if(_t0==DB_DATETIME || _t0==DB_BITMAP || _t0==DB_BIGINT)
-				return 0;
-		case DB_DATETIME:
-			if(_t0==DB_INT||_t0==DB_BIGINT)
-				return 0;
-			if(_t0==DB_BITMAP)
-				return 0;
-		case DB_DOUBLE:
-			break;
-		case DB_STRING:
-			if(_t0==DB_STR)
-				return 0;
-		case DB_STR:
-			if(_t0==DB_STRING || _t0==DB_BLOB)
-				return 0;
-		case DB_BLOB:
-			if(_t0==DB_STR || _t0==DB_STRING)
-				return 0;
-		case DB_BITMAP:
-			if (_t0==DB_INT)
-				return 0;
-		case DB_BIGINT:
-			if (_t0==DB_INT || _t0==DB_DATETIME || _t0==DB_BITMAP)
-				return 0;
+
+	switch(_t1) {
+	case DB_INT:
+		if(_t0==DB_BIGINT || _t0==DB_DATETIME || _t0==DB_BITMAP)
+			return 0;
+		break;
+
+	case DB_STRING:
+		if(_t0==DB_STR || _t0 == DB_BLOB)
+			return 0;
+		break;
+
+	case DB_STR:
+		if(_t0==DB_STRING || _t0==DB_BLOB)
+			return 0;
+		break;
+
+	case DB_BIGINT:
+		if(_t0==DB_INT || _t0==DB_DATETIME || _t0==DB_BITMAP)
+			return 0;
+		break;
+
+	case DB_BLOB:
+		if(_t0==DB_STR || _t0==DB_STRING)
+			return 0;
+		break;
+
+	case DB_DATETIME:
+		if(_t0==DB_INT || _t0==DB_BIGINT || _t0==DB_BITMAP)
+			return 0;
+		break;
+
+	case DB_BITMAP:
+		if(_t0==DB_INT || _t0==DB_BIGINT || _t0==DB_DATETIME)
+			return 0;
+		break;
+
+	default:
+		break;
 	}
+
 	return 1;
 }