LU-5061 obd: add rnb_ prefix to struct niobuf_remote members

LU-5061 obd: add rnb_ prefix to struct niobuf_remote members

Add the prefix rnb_ to the members of struct niobuf_remote. Delete the
relevant compat macros from ofd_internal.h.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: I51cfba173b63f8d4213faa223130fff829fdd66c
Reviewed-on: http://review.whamcloud.com/10452
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>