Fix ovs-vsctl executed in worlddump.py failed issue

add sudo before ovs-vsctl command.

Change-Id: I1a7dd9504da766beb452bd749e325931678de64e
Closes-Bug: #1576560
diff --git a/tools/worlddump.py b/tools/worlddump.py
index 238a23d..e1ef544 100755
--- a/tools/worlddump.py
+++ b/tools/worlddump.py
@@ -88,7 +88,8 @@
 
 
 def _bridge_list():
-    process = subprocess.Popen(['ovs-vsctl', 'list-br'], stdout=subprocess.PIPE)
+    process = subprocess.Popen(['sudo', 'ovs-vsctl', 'list-br'],
+                               stdout=subprocess.PIPE)
     stdout, _ = process.communicate()
     return stdout.split()