pdevs/mpi: remove START message

src/tests/mpi/cluster/main.cpp

@@ -203,9 +203,7 @@ void example_simple(int argc, char *argv[])
 
         steady_clock::time_point t1 = steady_clock::now();
 
-	std::cout << "START" << std::endl;
-	
-        rc.run();
+	rc.run();
 
         steady_clock::time_point t2 = steady_clock::now();