giveback petsc on mips

[Drew Parsons]

Hi wb team,

The build failure for petsc 3.9.4+dfsg1-3 on mips doesn't make sense. I 
wonder if it got caught in the middle of an openmpi package upgrade.  
Please try the build again.

      gb petsc_3.9.4+dfsg1-3 . mips

Thanks,
Drew