prov/tcp: Fix memory leak of dest_addr handling cm req

In tcpx_cm_recv_req, we duplicate the passive endpoint's
fi_info structure.  The dest_addr is then replaced without
the original dup'ed address being freed.  Free it first.

Fixes asan memory leak report.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>

prov/tcp/src/tcpx_conn_mgr.c

@@ -337,6 +337,7 @@ static void tcpx_cm_recv_req(struct util_wait *wait,
 		goto err2;
 
 	len = cm_entry->info->dest_addrlen = handle->pep->info->src_addrlen;
+	free(cm_entry->info->dest_addr);
 	cm_entry->info->dest_addr = malloc(len);
 	if (!cm_entry->info->dest_addr)
 		goto err3;