LU-946 lprocfs: List open files in filesystem

Added lprocfs file on MDT to list open files in per-export
directory for mdt.

Signed-off-by: Girish Shilamkar <gshilamkar@ddn.com>
Change-Id: If8f233d95dca4cd4c4044d85bd117a027dabd80e
Remove
FIx tests