usnic: update for libfabric API change

Use FI_ADDR_UNSPEC for posting a receive from an unspecified source.

opal/mca/btl/usnic/btl_usnic_module.c

@@ -2060,7 +2060,7 @@ static int init_one_channel(opal_btl_usnic_module_t *module,
         rseg->rs_len = segsize;
 
         rc = fi_recv(channel->ep, rseg->rs_protocol_header, segsize,
-                     NULL, FI_ADDR_NOTAVAIL, rseg);
+                     NULL, FI_ADDR_UNSPEC, rseg);
         if (0 != rc) {
             opal_show_help("help-mpi-btl-usnic.txt",
                            "internal error during init",

opal/mca/btl/usnic/btl_usnic_recv.h

@@ -28,7 +28,7 @@ opal_btl_usnic_post_recv_list(opal_btl_usnic_channel_t *channel)
 
     for (rseg = channel->repost_recv_head; NULL != rseg; rseg = rseg->rs_next) {
         rc = fi_recv(channel->ep, rseg->rs_protocol_header,
-                     rseg->rs_len, NULL, FI_ADDR_NOTAVAIL, rseg);
+                     rseg->rs_len, NULL, FI_ADDR_UNSPEC, rseg);
         if (0 != rc) {
             return rc;
         }