LU-8066 obd: make version_show sysfs compliant

LU-8066 obd: make version_show sysfs compliant

A patch was pushed upstream that added "lustre: "
to the lustre version sysfs file. This was
rejected due to the one item per sysfs rule.
Recently a patch was landed to update the
lustre tools to handle "lustre: " missing. Since
this is the case we can bring the version
sysfs file into compliance.

Change-Id: I74568d581b176c802f132cef3c022fe0fdded164
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/25632
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>