Remove DHCP lease files after test

Change-Id: I0b6084dbf5879a272d29d483bf08b8f8fb528586
diff --git a/TestON/tests/USECASE/SegmentRouting/dependencies/trellislib.py b/TestON/tests/USECASE/SegmentRouting/dependencies/trellislib.py
index b87ec9f..ebf6910 100644
--- a/TestON/tests/USECASE/SegmentRouting/dependencies/trellislib.py
+++ b/TestON/tests/USECASE/SegmentRouting/dependencies/trellislib.py
@@ -376,6 +376,7 @@
         if self.dhcpClient:
             self.cmd('kill -9 `cat %s`' % self.pidFile)
             self.cmd('rm -rf %s' % self.pidFile)
+            self.cmd('rm -rf %s' % self.leaseFile)
         if self.dhcpServer:
             self.cmd('kill -9 `cat %s`' % self.pidFile)
             self.cmd('rm -rf %s' % self.pidFile)