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/slirp.c b/net/slirp.c
index 8679be6..14a8d59 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -611,9 +611,8 @@
 
     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 
-    snprintf(nc->info_str, sizeof(nc->info_str),
-             "net=%s,restrict=%s", inet_ntoa(net),
-             restricted ? "on" : "off");
+    qemu_set_info_str(nc, "net=%s,restrict=%s", inet_ntoa(net),
+                      restricted ? "on" : "off");
 
     s = DO_UPCAST(SlirpState, nc, nc);