Fix compilation errors

- Rename `h_dest` to `h_target` in routine and in signature
- Remove extraneous logic

src/framework/MOM_diag_mediator.F90

@@ -1506,7 +1506,7 @@ subroutine post_data_3d(diag_field_id, field, diag_cs, is_static, mask, alt_h)
       allocate(remapped_field(size(field,1), size(field,2), diag%axes%nz))
       call vertically_reintegrate_diag_field(                                    &
         diag_cs%diag_remap_cs(diag%axes%vertical_coordinate_number), diag_cs%G,  &
-        diag_cs%h_extensive,
+        diag_cs%h_begin,                                                         &
         diag_cs%diag_remap_cs(diag%axes%vertical_coordinate_number)%h_extensive, &
         staggered_in_x, staggered_in_y, diag%axes%mask3d, diag_cs%missing_value, &
         field, remapped_field)
@@ -3258,7 +3258,7 @@ subroutine diag_update_remap_grids(diag_cs, alt_h, alt_T, alt_S, update_intensiv
     enddo
   endif
   if (update_extensive_local) then
-    CS%h_begin(:,:,:) = CS%h(:,:,:)
+    diag_cs%h_begin(:,:,:) = diag_cs%h(:,:,:)
     do i=1, diag_cs%num_diag_coords
       call diag_remap_update(diag_cs%diag_remap_cs(i), diag_cs%G, diag_cs%GV, diag_cs%US, h_diag, T_diag, S_diag, &
                              diag_cs%eqn_of_state, diag_cs%diag_remap_cs(i)%h_extensive)

src/framework/MOM_diag_remap.F90

@@ -312,12 +312,6 @@ subroutine diag_remap_update(remap_cs, G, GV, US, h, T, S, eqn_of_state, h_targe
     remap_cs%initialized = .true.
   endif
 
-  if (intensive) then
-    h_target => remap_cs%h
-  else
-    h_target => remap_cs%h_extensive
-  endif
-
   ! Calculate remapping thicknesses for different target grids based on
   ! nominal/target interface locations. This happens for every call on the
   ! assumption that h, T, S has changed.
@@ -493,11 +487,11 @@ subroutine diag_remap_calc_hmask(remap_cs, G, mask)
 end subroutine diag_remap_calc_hmask
 
 !> Vertically re-grid an already vertically-integrated diagnostic field to alternative vertical grid.
-subroutine vertically_reintegrate_diag_field(remap_cs, G, h, h_dest, staggered_in_x, staggered_in_y, &
+subroutine vertically_reintegrate_diag_field(remap_cs, G, h, h_target, staggered_in_x, staggered_in_y, &
                                              mask, missing_value, field, reintegrated_field)
   type(diag_remap_ctrl),  intent(in) :: remap_cs !< Diagnostic coodinate control structure
-  type(ocean_grid_type),  intent(in) :: G !< Ocean grid structure
-  real, dimension(:,:,:), intent(in) :: h      !< The thicknesses of the source grid
+  type(ocean_grid_type),  intent(in) :: G        !< Ocean grid structure
+  real, dimension(:,:,:), intent(in) :: h        !< The thicknesses of the source grid
   real, dimension(:,:,:), intent(in) :: h_target !< The thicknesses of the target grid
   logical,                intent(in) :: staggered_in_x !< True is the x-axis location is at u or q points
   logical,                intent(in) :: staggered_in_y !< True is the y-axis location is at v or q points