transport/ofi: zero max_buffered_send before fi_getinfo hint

Let the provider advertise its natural inject_size rather than
requiring it to be at least sizeof(long double). The returned
inject_size is adopted immediately after fi_getinfo.

Author: bcmIntc

src/transport_ofi.c

@@ -1470,7 +1470,9 @@ int query_for_fabric(struct fabric_info *info)
     struct fi_fabric_attr fabric_attr = {0};
     struct fi_ep_attr   ep_attr = {0};
 
-    shmem_transport_ofi_max_buffered_send = sizeof(long double);
+    /* Hint 0 = no minimum inject requirement; provider returns its natural
+     * inject_size, which is adopted below after fi_getinfo. */
+    shmem_transport_ofi_max_buffered_send = 0;
 
     fabric_attr.prov_name = info->prov_name;