ocfs2/dlm: Create debugfs dirs

This patch creates the debugfs directories that will hold the
files to be used to dump the dlm state.

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>