net: introduce qemu_set_info_str() function

Embed the setting of info_str in a function.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
diff --git a/net/vde.c b/net/vde.c
index 1083916..c0a0866 100644
--- a/net/vde.c
+++ b/net/vde.c
@@ -98,8 +98,7 @@
 
     nc = qemu_new_net_client(&net_vde_info, peer, model, name);
 
-    snprintf(nc->info_str, sizeof(nc->info_str), "sock=%s,fd=%d",
-             sock, vde_datafd(vde));
+    qemu_set_info_str(nc, "sock=%s,fd=%d", sock, vde_datafd(vde));
 
     s = DO_UPCAST(VDEState, nc, nc);