pml/cm: fix a problem introduced with cuda support

PR #8536 introduced a regression in non-cuda environments
when an application is using derived, but continguous datatypes.

Related to #8905.

Signed-off-by: Howard Pritchard <[email protected]>

Author: hppritcha

ompi/mca/pml/cm/pml_cm_sendreq.h

@@ -15,6 +15,8 @@
  * Copyright (c) 2015      Research Organization for Information Science
  *                         and Technology (RIST). All rights reserved.
  * Copyright (c) 2017      Intel, Inc. All rights reserved
+ * Copyright (c) 2021      Triad National Security, LLC. All rights
+ *                         reserved.
  * $COPYRIGHT$
  *
  * Additional copyrights may follow
@@ -31,6 +33,7 @@
 #include "ompi/mca/pml/pml.h"
 #include "ompi/mca/mtl/mtl.h"
 #include "opal/prefetch.h"
+#include "opal/runtime/opal_params.h"
 
 struct mca_pml_cm_send_request_t {
     mca_pml_cm_request_t req_base;
@@ -247,9 +250,11 @@ do {                                                                    \
         MCA_PML_CM_SWITCH_CUDA_CONVERTOR_OFF(flags, datatype, count);   \
         (req_send)->req_base.req_convertor.flags |= flags;              \
         /* Sets CONVERTOR_CUDA flag if CUDA buffer */                   \
-        opal_convertor_prepare_for_send(                                \
-            &req_send->req_base.req_convertor,                          \
-            &datatype->super, count, buf );                             \
+        if (opal_built_with_cuda_support) {                             \
+            opal_convertor_prepare_for_send(                            \
+                &req_send->req_base.req_convertor,                      \
+                &datatype->super, count, buf );                         \
+        }                                                               \
     } else {                                                            \
         MCA_PML_CM_SWITCH_CUDA_CONVERTOR_OFF(flags, datatype, count);   \
         opal_convertor_copy_and_prepare_for_send(                       \