Change benchmark ingest took metric to total time (#268)

Measuring total took time will give a better picture of how long it
will take to make a particular set of documents searchable.

Signed-off-by: John Mazanec <jmazane@amazon.com>

benchmarks/perf-tool/README.md

@@ -226,7 +226,7 @@ Ingests a dataset of vectors into the cluster.
 
 | Metric Name | Description | Unit |  
 | ----------- | ----------- | ----------- |
-| took | Took times returned per bulk request aggregated as total, p50, p90 and p99 (when applicable). Note - this number does not mean the time it took to made the vectors searchable. Time from the refresh step should be looked at as well to determine this.| ms |
+| took | Total time to ingest the dataset into the index.| ms |
 
 #### query
 

benchmarks/perf-tool/okpt/test/steps/steps.py

@@ -279,7 +279,6 @@ def __init__(self, step_config: StepConfig):
                                      Context.INDEX)
 
     def _action(self):
-        results = {}
 
         def action(doc_id):
             return {'index': {'_index': self.index_name, '_id': doc_id}}
@@ -295,13 +294,9 @@ def action(doc_id):
             index_responses.append(result)
             id += self.bulk_size
 
-        results['took'] = [
-            float(index_response['took']) for index_response in index_responses
-        ]
-
         self.dataset.reset()
 
-        return results
+        return {}
 
     def _get_measures(self) -> List[str]:
         return ['took']