Fixed BACNET_APPLICATION_DATA_VALUE declarations to be initialized so that the next pointer is NULL by default. (#814)

src/bacnet/basic/object/calendar.c

@@ -573,7 +573,7 @@ bool Calendar_Write_Property(BACNET_WRITE_PROPERTY_DATA *wp_data)
 {
     bool status = false; /* return value */
     int len = 0;
-    BACNET_APPLICATION_DATA_VALUE value;
+    BACNET_APPLICATION_DATA_VALUE value = { 0 };
     int iOffset;
     BACNET_CALENDAR_ENTRY entry;
     bool pv_old;