osc/pt2pt: reset all_sync sync object before sending complete messages

This commit fixes a bug that occurs when a post message comes in when
sending complete messages or while waiting for all outgoing messages
to flush. In that case the post message might get incorrecly
associated with the ending sync object.

References open-mpi#1012

Signed-off-by: Nathan Hjelm <[email protected]>

(cherry picked from open-mpi/ompi@864f88a)

Author: hjelmn

ompi/mca/osc/pt2pt/osc_pt2pt_active_target.c

@@ -321,6 +321,9 @@ int ompi_osc_pt2pt_complete (ompi_win_t *win)
 
     peers = sync->peer_list.peers;
 
+    /* need to reset the sync here to avoid processing incorrect post messages */
+    ompi_osc_pt2pt_sync_reset (sync);
+
     OPAL_THREAD_UNLOCK(&module->lock);
 
     OPAL_OUTPUT_VERBOSE((50, ompi_osc_base_framework.framework_output,
@@ -396,8 +399,6 @@ int ompi_osc_pt2pt_complete (ompi_win_t *win)
         opal_condition_wait(&module->cond, &module->lock);
     }
 
-    ompi_osc_pt2pt_sync_reset (sync);
-
     /* unlock here, as group cleanup can take a while... */
     OPAL_THREAD_UNLOCK(&module->lock);