mtl/ofi: replace OMPI_UNLIKELY with OPAL version

one off patch for v4.0.x.  for some reason commit on master
didn't have this problem.

Signed-off-by: Howard Pritchard <howardp@lanl.gov>
(cherry picked from commit 5f3dbdb5c8)

Note that this commit is actually a cherry-pick from the v4.0.x
branch.  This is the opposite direction than what we nornmally do: we
usually commit to master first and then cherry-pick to the release
branches (vs. the other way around).

As is probably evident from the original commit message above, through
a comedy of errors, this commit was actually applied to the v4.0.x
branch first and then cherry-picked back to master (i.e., the problem
*did* exist in the original master commit
3aca4af548, but it was not recongized at
the time).

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

ompi/mca/mtl/ofi/mtl_ofi.h

@@ -2,6 +2,8 @@
  * Copyright (c) 2013-2018 Intel, Inc. All rights reserved
  * Copyright (c) 2017      Los Alamos National Security, LLC. All rights
  *                         reserved.
+ * Copyright (c) 2019      Triad National Security, LLC. All rights
+ *                         reserved.
  *
  * Copyright (c) 2018      Amazon.com, Inc. or its affiliates.  All Rights reserved.
  * $COPYRIGHT$
@@ -562,7 +564,7 @@ ompi_mtl_ofi_isend_generic(struct mca_mtl_base_module_t *mtl,
     sep_peer_fiaddr = fi_rx_addr(endpoint->peer_fiaddr, ctxt_id, ompi_mtl_ofi.rx_ctx_bits);
 
     ompi_ret = ompi_mtl_datatype_pack(convertor, &start, &length, &free_after);
-    if (OMPI_UNLIKELY(OMPI_SUCCESS != ompi_ret)) return ompi_ret;
+    if (OPAL_UNLIKELY(OMPI_SUCCESS != ompi_ret)) return ompi_ret;
 
     ofi_req->buffer = (free_after) ? start : NULL;
     ofi_req->length = length;