LU-16518 ldlm: fix unused-but-set-variable warnings

LU-16518 ldlm: fix unused-but-set-variable warnings

In ldlm_flock_completion_ast(), obd* is not being
used. Remove it to silence the Clang compiler warning.

Test-Parameters: trivial
Signed-off-by: Timothy Day <timday@amazon.com>
Change-Id: Idc8d0fd9a351b4bb328a0956eabd2026460cdfe1
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/58180
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Max Wang <wamax@amazon.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>