mpi/tests/early_stuff: return 0 instead of 77, some mpi implementations do not like 77

mpi/tests/early_stuff.c

@@ -27,7 +27,7 @@ int main(int argc, char **argv)
 	if (!mpi_init)
 		MPI_Finalize();
 
-	return STARPU_TEST_SKIPPED;
+	return 0;
 }
 
 #else