net: Monitor command set_link finds only VLAN clients, fix

Clients not associated with a VLAN exist since commit d80b9fc6.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>
(cherry picked from commit 2583ba97)

net.c

@@ -1243,6 +1243,7 @@ void do_set_link(Monitor *mon, const QDict *qdict)
             }
         }
     }
+    vc = qemu_find_netdev(name);
 done:
 
     if (!vc) {