staging: lustre: changelog: Proper record remapping

Fixed changelog_remap_rec() to correctly remap records emitted
with jobid_var=disabled, i.e. delivered by new servers but with
no jobid field.

Signed-off-by: Henri Doreau <henri.doreau@cea.fr>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5862
Reviewed-on: http://review.whamcloud.com/12574


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Robert Read <robert.read@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>