LU-6142 uapi: Fix style issues for lustre_disk.h

LU-6142 uapi: Fix style issues for lustre_disk.h

This patch fixes issues reported by checkpatch
for file lustre/include/lustre_disk.h

Test-Parameters: trivial
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: I20cc1784602b7e95a5c1541851684d3c2199be1b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53919
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Oleg Drokin <green@whamcloud.com>