staging/lustre/osc: Check return code for lu_kmem_init

lu_kmem_init can fail and returns has a return code.
Check for this return code in lu_kmem_init.

This issue was found during 2gb VM Racer testing

Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3063
Lustre-change: http://review.whamcloud.com/6514


Signed-off-by: Keith Mannthey <keith.mannthey@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>