ctdb-scripts: Avoid direct /proc access

ctdb-scripts: Avoid direct /proc access

The main reason for this is to facilitate testing.

Avoid some /proc accesses entirely by using ps(1) (which can be
replaced by a stub when testing) because this script might as well be
more portable in case anyone wants to add lock debugging for a
non-Linux platform.  While the "state" format specification isn't
POSIX-compliant, it works on both Linux and FreeBSD so it is a
reasonable improvement.

Signed-off-by: Martin Schwenke <martin@meltin.net>
Reviewed-by: Amitay Isaacs <amitay@gmail.com>