apps(model_diagnostics): fix invalid callback

apps/model-diagnostics/model_diagnostics.cpp

@@ -12,11 +12,14 @@ using namespace cv;
 using namespace dnn;
 
 
-static void diagnosticsErrorCallback(const Exception& exc)
+static
+int diagnosticsErrorCallback(int /*status*/, const char* /*func_name*/,
+                             const char* /*err_msg*/, const char* /*file_name*/,
+                             int /*line*/, void* /*userdata*/)
 {
-    CV_UNUSED(exc);
     fflush(stdout);
     fflush(stderr);
+    return 0;
 }
 
 static std::string checkFileExists(const std::string& fileName)
@@ -54,7 +57,7 @@ int main( int argc, const char** argv )
     CV_Assert(!model.empty());
 
     enableModelDiagnostics(true);
-    redirectError((ErrorCallback)diagnosticsErrorCallback, NULL);
+    redirectError(diagnosticsErrorCallback, NULL);
 
     Net ocvNet = readNet(model, config, frameworkId);