LU-5061 obd: add lnb_ prefix to members of struct niobuf_local

LU-5061 obd: add lnb_ prefix to members of struct niobuf_local

Add the prefix lnb_ to the members of struct niobuf_local that do not
already have it. Delete the relevant compat macros from
ofd_internal.h. Change the struct dentry *lnb_dentry member to void
*lnb_data as it is not used to hold a pointer to struct dentry.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I65ef2b697dbb13d62aa8c408f68732f569f15a48
Reviewed-on: http://review.whamcloud.com/10451
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>