osc/rdma: now that the access epoch is not open after MPI_Win_create* we

need to enable the access epoch in MPI_Win_fence.

I missed this change when I fixed the semantics of MPI_Win_create. With
this commit our one-sided MTT runs are now running clean.

cmr=v1.7.5:reviewer=dgoodell

This commit was SVN r31041.

ompi/mca/osc/rdma/osc_rdma_active_target.c

@@ -80,6 +80,7 @@ ompi_osc_rdma_fence(int assert, ompi_win_t *win)
 
     /* short-circuit the noprecede case */
     if (0 != (assert & MPI_MODE_NOPRECEDE)) {
+        module->active_eager_send_active = true;
         ret = module->comm->c_coll.coll_barrier(module->comm,
                                                 module->comm->c_coll.coll_barrier_module);
         OPAL_OUTPUT_VERBOSE((50, ompi_osc_base_framework.framework_output,