revert: Didn't mean to request merge of last commit so have reverted it

This reverts commit bb3e5552.

pyicon/pyicon_calc_xr.py

@@ -355,7 +355,7 @@ def xr_calc_edge2cell_coeff_cc(ds_IcD):
 
 def xr_edges2cell(ds_IcD, ve, dze, dzc, edge2cell_coeff_cc=None, fixed_vol_norm=None):
     if fixed_vol_norm is None:
-        fixed_vol_norm = xr_calc_fixed_volume_norm(ds_IcD)
+        fixed_vol_norm = xr_calc_fixed_vol_norm(ds_IcD)
     if edge2cell_coeff_cc is None:
         edge2cell_coeff_cc = xr_calc_edge2cell_coeff_cc(ds_IcD)
     if ve.dims != dze.dims: