osc/pt2pt: fix compiler warning

Remove unused variable.

Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

ompi/mca/osc/pt2pt/osc_pt2pt_frag.c

@@ -5,6 +5,7 @@
  *                         reserved.
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
+ * Copyright (c) 2017      Cisco Systems, Inc.  All rights reserved
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -153,7 +154,6 @@ int ompi_osc_pt2pt_frag_flush_pending_all (ompi_osc_pt2pt_module_t *module)
 int ompi_osc_pt2pt_frag_flush_target (ompi_osc_pt2pt_module_t *module, int target)
 {
     ompi_osc_pt2pt_peer_t *peer = ompi_osc_pt2pt_peer_lookup (module, target);
-    ompi_osc_pt2pt_frag_t *frag;
     int ret = OMPI_SUCCESS;
 
     OPAL_OUTPUT_VERBOSE((50, ompi_osc_base_framework.framework_output,