update for mpi_lam so it allows multiple runs on a overcommitted node.

src/plugins/mpi/lam/mpi_lam.c

@@ -80,7 +80,7 @@ int mpi_p_thr_create(srun_job_t *job)
 
 int mpi_p_single_task()
 {
-	return true;
+	return false;
 }
 
 int mpi_p_exit()

src/srun/launch.c

@@ -138,7 +138,7 @@ launch(void *arg)
 			r->task_flags |= TASK_PARALLEL_DEBUG;
 
 		/* Node specific message contents */
-		if (slurm_mpi_single_task_per_node ())
+		if (slurm_mpi_single_task_per_node ()) 
 			r->tasks_to_launch = 1; 
 		else
 			r->tasks_to_launch = job->ntask[i];