Set pollingMode to false explicitly

Author: Boisy Pitre

lib/bus/drivewire/dwcom/fnDwCom.h

@@ -25,7 +25,7 @@ class DwCom
         BECKER
     };
 
-    bool pollingMode;
+    bool pollingMode = false;
 
     // Host & client channel queues
     std::vector<char> outgoingChannel[16];