zapi: Harden dispatch to prevent invalid data

Relate-to: https://github.com/SiliconLabsSoftware/z-wave-engine-application-layer/issues/42
Signed-off-by: Philippe Coval <[email protected]>

Author: rzr

applications/zpc/components/zwave_api/src/zwapi_init.c

@@ -136,7 +136,7 @@ bool zwapi_poll()
   zwapi_session_enqueue_rx_frames();
   bool more_frames = zwapi_session_dequeue_frame(&frame, &len);
 
-  if (frame) {
+  if (frame && len >=1) {
     zwave_api_protocol_rx_dispatch(frame, len);
     free(frame);
   }