vhost: show vhost may display garbage after the interface name

DBGvpp# show vhost-user
Virtio vhost-user interfaces
Global:
  coalesce frames 32 time 1e-3
  number of rx virtqueues in interrupt mode: 0
Interface: VirtualEthernet0/0/0�?x�D (ifindex 3)

The fix is to use format_vnet_hw_if_index_name rather than hi->name. The former
format the name with %v rather than %s

Change-Id: If4d275e1eb249cf87b2d6b796b42f24769f9e3e3
Signed-off-by: Steven <sluong@cisco.com>

src/vnet/devices/virtio/vhost_user.c

@@ -1777,8 +1777,9 @@ show_vhost_user_command_fn (vlib_main_t * vm,
     {
       hi = vnet_get_hw_interface (vnm, hw_if_indices[i]);
       vui = pool_elt_at_index (vum->vhost_user_interfaces, hi->dev_instance);
-      vlib_cli_output (vm, "Interface: %s (ifindex %d)",
-		       hi->name, hw_if_indices[i]);
+      vlib_cli_output (vm, "Interface: %U (ifindex %d)",
+		       format_vnet_hw_if_index_name, vnm, hw_if_indices[i],
+		       hw_if_indices[i]);
 
       vlib_cli_output (vm, "virtio_net_hdr_sz %d\n"
 		       " features mask (0x%llx): \n"