LU-8191 obdclass: add static and remove functions

LU-8191 obdclass: add static and remove functions

Static analysis shows that a number of functions
could be made static. This patch declares several
functions in obdclass static.

There are a few functions which are never called
anywhere. These are removed. Additionally, there
is some debugging code (added 15 years ago) that
has also been removed.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I5f1d438c9663e62789d26093ec9bdd5d76a3060a
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/51440
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Neil Brown <neilb@suse.de>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: jsimmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>