dns_name_downcase() was not calling isc_buffer_add(), so buffer would always be empty.  This would cause name digesting to fail as well. Remove some unused variables left over from the removal of local compression.
dns_name_downcase() was not calling isc_buffer_add(), so buffer would always
be empty.  This would cause name digesting to fail as well.
Remove some unused variables left over from the removal of local compression.

each/bind9-collab,pecharmin/bind9,pecharmin/bind9,pecharmin/bind9,each/bind9-collab,each/bind9-collab,pecharmin/bind9,each/bind9-collab,each/bind9-collab,each/bind9-collab,pecharmin/bind9,pecharmin/bind9