Bug in melt rate computation in "coupled" mode

[xylar]

There is a bug in "coupled" mode here:
https://github.com/MPAS-Dev/MPAS-Model/blob/e3sm/develop/src/core_ocean/shared/mpas_ocn_surface_land_ice_fluxes.F#L810-L813
where T0 is accessed before it is computed.