checkpatch.py: A simple script for finding patch issues

checkpatch.py: A simple script for finding patch issues

Most projects have a checkpatch facility, which can be used as a pre-commit
sanity check. This introduces such a mechanism to the Open vSwitch project
to catch some of the more silly formatting mistakes which can occur. It is
not meant to replace good code review practices, but it can help eliminate
the silly code review issues which get added.

Suggested-by: Mauricio Vásquez <mauricio.vasquezbernal@studenti.polito.it>
Signed-off-by: Aaron Conole <aconole@redhat.com>
[blp@ovn.org adjusted long line threshold and treatment of terminal]
Signed-off-by: Ben Pfaff <blp@ovn.org>