LU-4800 obdclass: runtime load lustre client when needed

LU-4800 obdclass: runtime load lustre client when needed

Manually force loading of lustre.ko during client
mounts with request_module for cases where
autoloading doesn't happen.

Signed-off-by: Bob Glossman <bob.glossman@intel.com>
Change-Id: I807fc5cd04cf5a97d9c131208b7b13037dc10ee6
Reviewed-on: http://review.whamcloud.com/10587
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Yang Sheng <yang.sheng@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>