staging: lustre: llog: keep llog ctxt indices constant

The llog context id table cannot be shrunk easily because that
will cause index shifting and incompatibility between old client
and new server and vice versa.

Patch moves llog_ctxt_id table to the lustre_idl.h because this is
wire protocol data, these values are added to the wirecheck.

Signed-off-by: Mikhail Pershin <mike.pershin@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5218
Reviewed-on: http://review.whamcloud.com/10758


Reviewed-by: Andreas Dilger <andreas.dilger@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>