Changed variable name to fix minor bug

[bbixler500]

Changed variable name to fix minor bug

Description

The hwp_pmx agent references a variable contained within the hwp_supervisor agent. In the supervisor agent the variable name changed, but this change was not also applied to the pmx agent. This pull request changes the pmx variable to the newer convention.

Motivation and Context

Fixes a bug https://github.com//issues/580#event-11089174660

How Has This Been Tested?

It has not been tested, but the pull request only changes a single variable

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[jlashner]

good catch, thanks!