How to access Developer's performance when he finishes a story in Jira?

[Le Nguyet Minh]

We are working on software development and we use Jira as a means of work management.
As we start a story or a bug, developer will estimate time to finish that story. Ex: Story 1 with 6 points, story 2 with 4 points. Suppose that 10 points are equals to 8 working hour/day. So if Developer X finishes these two story in 8 hours, it considers that they complete their task in a day. 
The case is: When X finishes story 1 (the story will start from To do column => In progress Column) and drags it to Checking column. At this time QA or the monitor will check the story. If the story fails with some bugs (EX: 5 bugs), the QA/ monitor will drag it to Not OK column and Developer X has to take back the story to fix the 5 bugs reported by QA.

The question is: How to assess the story at this time when developer has to spend more time to fix these 5 bugs (Even when it takes a half day  to fix only one bug, that means time spent exceeds 6 points as it was assigned from the start). At this moment, how to calculate points for the Story 1 when it takes more time to fix these 5 bugs? Does Jira has any feature to measure this in order to access developer's performance in a story? If X does the story carefully from the beginning, nothing to discuss here. But if he fails the story 1 with 5 bugs, how to monitor and access his performance?

Suppose that 5 days a week he is assigned 8 stories  but 5 out of 8 stories are done with bugs, how to manage his performance? 

Thank you for reading my question! Hope to get your proper answer! :)