staging: lustre: obd: validate open handle cookies

Add a const void *h_owner member to struct portals_handle. Add a const
void *owner parameter to class_handle2object() which must be matched
by the h_owner member of the handle in addition to the cookie.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3233
Reviewed-on: http://review.whamcloud.com/6938


Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>