LU-6142 ldlm: Fix style issues for ldlm_extent.c

LU-6142 ldlm: Fix style issues for ldlm_extent.c

This patch fixes issues reported by checkpatch
for file lustre/ldlm/ldlm_extent.c

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I9cecd1f377f33f3d4129cddcd7b59c3a7c003e04
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49536
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>