bugfix FSISPH and constant boundaries

[jmpearl]

Summary

• the damaged pressure was being initialized at 2x. This would cause issues for problems w/ constant boundaries.

---

ToDo :

• Annotate RELEASE_NOTES.md with notable changes.
• Create LLNLSpheral PR pointing at this branch. (PR#)
• LLNLSpheral PR has passed all tests.

[jmikeowen]

Assuming the damaged pressure is always otherwise initialized this is fine. Another fix would have been to initialize here with
mDamagedPressure = this->pressure();
rather than adding it. Why was this done with += originally?

[jmpearl]

That is a great question and i asked myself the same thing. I can't remember why I had it as plus equals originally. I think the damaged pressure should always be initialized now through the call to the pressure update policy. Do you see any edge cases where that might not be the case?

[jmikeowen]

Naw, I think you should be good as is. Still have to ask about having a test that would catch this error of course... :-)

[jmpearl]

I'm going to merge this now just to get the change in and punt on the test to a later date