Fix various warnings

-Wunused-parameter
-Wreorder
-Wsign-compare
-Wunused-private-field

examples/multiple-transports/Sink.cxx

@@ -23,8 +23,6 @@ Sink::Sink()
     : fMaxIterations(0)
     , fNumIterations1(0)
     , fNumIterations2(0)
-    , fReceived1(false)
-    , fReceived2(false)
 {
     // register a handler for data arriving on "data" channel
     OnData("data1", &Sink::HandleData1);

examples/multiple-transports/Sink.h

@@ -36,8 +36,6 @@ class Sink : public FairMQDevice
     uint64_t fMaxIterations;
     uint64_t fNumIterations1;
     uint64_t fNumIterations2;
-    bool fReceived1;
-    bool fReceived2;
 };
 
 } // namespace example_multiple_transports

examples/region/Sampler.cxx

@@ -38,7 +38,7 @@ void Sampler::InitTask()
     fRegion = FairMQUnmanagedRegionPtr(NewUnmanagedRegionFor("data",
                                                              0,
                                                              10000000,
-                                                             [this](void* data, size_t size, void* hint) { // callback to be called when message buffers no longer needed by transport
+                                                             [this](void* /*data*/, size_t /*size*/, void* /*hint*/) { // callback to be called when message buffers no longer needed by transport
                                                                  --fNumUnackedMsgs;
                                                                  if (fMaxIterations > 0)
                                                                  {