staging: lustre: 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. 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>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5061
Reviewed-on: http://review.whamcloud.com/10451


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>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>