Fix InfluxDB storage total() method pagination

Change-Id: I135e0a5ba02ee84dd057ab0fa7c2a2c6f47f2e7b

cloudkitty/storage/v2/influx.py

@@ -365,5 +365,5 @@ class InfluxStorage(v2_storage.BaseStorage):
             output.sort(key=lambda x: [x[group] for group in groupby])
         return {
             'total': len(output),
-            'results': output[offset:limit] if paginate else output,
+            'results': output[offset:offset + limit] if paginate else output,
         }

cloudkitty/tests/storage/v2/test_storage_unit.py

@@ -244,7 +244,7 @@ class StorageUnitTest(TestCase):
                 begin=begin,
                 end=end,
                 offset=offset,
-                limit=offset + 2,
+                limit=2,
                 groupby=['type'])
             # there are seven metric types
             self.assertEqual(chunk['total'], 7)