Santosh,
This is a really good comment. I looked at the code of the form, usp_update_control.htmpl, and it looks like the code that adds the buttons are throughout. I don't seem to see any if/then statements that the button should only show if xFlow is installed (maybe I'm missing something though).
The form could be customized to remove all references, but I'm concerned that since there are so many references that there is a chance of some of the code removal interfering with something else.
This may be a good one to create a ticket off of though to see if Engineering can review further, the way it works doesn't feel right.