LU-18420 llite: Use enum mds_ibits_locks instead of __u64

LU-18420 llite: Use enum mds_ibits_locks instead of __u64

This patch uses enum mds_ibits_locks instead of generic
__u64. This patch has no functional changes.

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I2d9ad5001977a532f2d7c3242ce2e40f38974c5e
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/56877
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>