ocfs2/dlm: Dump the dlm state in a debugfs file

This patch dumps the dlm state (dlm_ctxt) into a debugfs file.
Useful for debugging.

Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>