[2576] use the generic delete_zone in b10-loadzone instead of sqlite3 hack

src/bin/loadzone/loadzone.py.in

@@ -200,29 +200,6 @@ class LoadZoneRunner:
         logger.info(LOADZONE_SQLITE3_USING_DEFAULT_CONFIG, default_db_file)
         return '{"database_file": "' + default_db_file + '"}'
 
-    def __cancel_create(self):
-        '''sqlite3-only hack: delete the zone just created on load failure.
-
-        This should eventually be done via generic datasrc API, but right now
-        we don't have that interface.  Leaving the zone in this situation
-        is too bad, so we handle it with a workaround.
-
-        '''
-        if self._datasrc_type is not 'sqlite3':
-            return
-
-        import sqlite3          # we need the module only here
-        import json
-
-        # If we are here, the following should basically succeed; since
-        # this is considered a temporary workaround we don't bother to catch
-        # and recover rare failure cases.
-        dbfile = json.loads(self._datasrc_config)['database_file']
-        with sqlite3.connect(dbfile) as conn:
-            cur = conn.cursor()
-            cur.execute("DELETE FROM zones WHERE name = ?",
-                        [self._zone_name.to_text()])
-
     def _report_progress(self, loaded_rrs):
         '''Dump the current progress report to stdout.
 
@@ -274,10 +251,10 @@ class LoadZoneRunner:
                 self.__loaded_rrs >= self._report_interval):
                 sys.stdout.write('\n')
         except Exception as ex:
-            # release any remaining lock held in the client/loader
-            loader, datasrc_client = None, None
+            # release any remaining lock held in the loader
+            loader = None
             if created:
-                self.__cancel_create()
+                datasrc_client.delete_zone(self._zone_name)
                 logger.error(LOADZONE_CANCEL_CREATE_ZONE, self._zone_name,
                              self._zone_class)
             raise LoadFailure(str(ex))