OFI: patch OFI MTL for GNI provider

Uncovered a problem using the GNI provider with the OFI MTL.
See ofiwg/libfabric#6194.

Related to #8001

Signed-off-by: Howard Pritchard <hppritcha@gmail.com>

Author: hppritcha

ompi/mca/mtl/ofi/mtl_ofi_component.c

@@ -940,6 +940,17 @@ ompi_mtl_ofi_component_init(bool enable_progress_threads,
         goto error;
     }
 
+    /**
+     * Unfortunately the attempt to implement FI_MR_SCALABLE in the GNI provider
+     * doesn't work, at least not well.  Since we're asking for the 1.5 libfabric
+     * API now, we have to tell GNI we want to use Mr. Basic.  Using FI_MR_BASIC
+     * rather than FI_MR_VIRT_ADDR | FI_MR_ALLOCATED | FI_MR_PROV_KEY to stay
+     * compatible with older libfabrics.
+     */
+    if (!strncmp(prov->fabric_attr->prov_name,"gni",3)) {
+         prov->domain_attr->mr_mode = FI_MR_BASIC;
+    }
+
     /**
      * Create the access domain, which is the physical or virtual network or
      * hardware port/collection of ports.  Returns a domain object that can be