Grab "ierr" when it's provided
Grab "ierr" when it's provided

Hopefully this will fix the regression in -Werror builds with prior
PETSc versions

idaholab/moose,idaholab/moose,laagesen/moose,laagesen/moose,idaholab/moose,laagesen/moose,laagesen/moose,idaholab/moose,idaholab/moose,laagesen/moose