fix potential arrary overflow problem of _recvBuffer (#214)

* fix potential arrary overflow problem of _recvBuffer

* Update src/utility/HCI.cpp

make the code eaiser to read

Co-authored-by: Alexander Entinger <consulting@lxrobotics.com>

* optimize code of potential overflow _recvBuffer

* add the debug msg when the _recvBuffer overflow

Co-authored-by: Alexander Entinger <consulting@lxrobotics.com>

Author: bigbearishappy

src/utility/HCI.cpp

@@ -112,6 +112,13 @@ void HCIClass::poll(unsigned long timeout)
 
   while (HCITransport.available()) {
     byte b = HCITransport.read();
+	
+    if (_recvIndex >= sizeof(_recvBuffer)) {
+        _recvIndex = 0;
+        if (_debug) {
+            _debug->println("_recvBuffer overflow");
+        }
+    }
 
     _recvBuffer[_recvIndex++] = b;