VPP-237: Checkstyle script to check for new checkstyle breakage

VPP-237: Checkstyle script to check for new checkstyle breakage

indent is... cantankerous

It sometimes happens that if you run

indent A

resulting in A'

and then

indent A'

you get back A.  Since the check here is premised on being able
to run indent and not see any changed... we have to run it twice
to be sure.

Change-Id: I5b73e02f5996d8a01ec2e46741affbc6d62da6c9
Signed-off-by: Ed Warnicke <eaw@cisco.com>