Make sure buffer is cleared when first connecting

When first connecting in onosdriver, make sure we clear the buffer

Change-Id: I9a1d7e9c8ab166b9f6d44207aac38841e6ee5b57
diff --git a/TestON/drivers/common/cli/onosdriver.py b/TestON/drivers/common/cli/onosdriver.py
index e47d34d..d948748 100755
--- a/TestON/drivers/common/cli/onosdriver.py
+++ b/TestON/drivers/common/cli/onosdriver.py
@@ -132,6 +132,7 @@
 
             if self.handle:
                 self.handle.sendline( "cd " + self.home )
+                self.handle.expect( "cd " + self.home )
                 self.handle.expect( self.prompt )
                 return self.handle
             else: