change to non-blocking poll

This commit was SVN r2184.

src/runtime/ompi_progress.c

@@ -5,7 +5,7 @@
 
 void ompi_progress(void)
 {
-    ompi_event_loop(OMPI_EVLOOP_ONCE);
+    ompi_event_loop(OMPI_EVLOOP_NONBLOCK);
     mca_pml.pml_progress();
 }