dlm: don't kref_init rsbs created for toss list

This patch removes a kref_init() that isn't necessary because the rsb is
created for toss list. Under toss list the rsb should not have any
reference counting logic. If in theory the rsb gets to into keep list
then a kref_init() for res_ref will be initiated.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>