staging: lustre: ldlm: remove ldlm_policy_data_t typedef usage from code

staging: lustre: ldlm: remove ldlm_policy_data_t typedef usage from code

Replace usage of ldlm_policy_data_t with named enums
to conform to upstream coding style.

Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6142
Reviewed-on: http://review.whamcloud.com/15300
Reviewed-on: http://review.whamcloud.com/15301
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: frank zago <fzago@cray.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>