LU-17673 llite: ll_options() to release the string

LU-17673 llite: ll_options() to release the string

the final strsep() sets opts to NULL so kfree() becomes no-op.

Signed-off-by: Alex Zhuravlev <bzzz@whamcloud.com>
Change-Id: I18a0d3556fa2932c217d9e705af9e5b5720a364b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/54554
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>