remove energy_fixer, compute_energy from prim_driver_mod

It seems that in master homme parameter energy_fixer is gone and logic around compute_energy is gone, too. these cause extra calls to (unknown for now) prim_energy_halftimes. I will adjust the logic to the one in master homme.

```
if (MODULO(nstep_end,statefreq)==0 .or. nstep_end==tl%nstep0) then
compute_diagnostics= .true.
compute_energy = .true.
endif
if(disable_diagnostics) compute_diagnostics= .false.
...
! E(1) Energy after CAM forcing
if (compute_energy) then
call t_startf("prim_energy_halftimes")
call prim_energy_halftimes(elem,hvcoord,tl,1,.true.,nets,nete)
call t_stopf("prim_energy_halftimes")
endif
```