LU-18921 ldlm: make client_obd_cleanup return void

LU-18921 ldlm: make client_obd_cleanup return void

client_obd_cleanup() can never fail and it always returns
0. Make the function return void instead and fix all of the
callers.

Test-Parameters: trivial
Fixes: 911b6167a37c ("LU-3810 obd: Cleanup client import if client_obd_setup fail")
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: I5a5987b4fafb712c35943620235620c6370a9f76
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58761
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Vandana Rungta <vrungta@amazon.com>
Reviewed-by: Shaun Tancheff <shaun.tancheff@hpe.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>