python_modules/ptypes.py/EnumBaseType.c_enumname: add missing return to fix broken enums generation
python_modules/ptypes.py/EnumBaseType.c_enumname: add missing return to fix broken enums generation

Fixes the resulting enums.h from the invocation of:
./spice_codegen.py --generate-enums spice.proto spice-protocol/spice/enums.h

Right now any enum will contain None as the enum members, with this fix
it will contain the real enum members, i.e. SPICE_FOO.

Fantu/spice-common,elmarco/spice-common,freedesktop-unofficial-mirror/spice__spice-common,SPICE/spice-common,elmarco/spice-common,elmarco/spice-common,Fantu/spice-common,SPICE/spice-common,fgouget/spice-common,elmarco/spice-common,freedesktop-unofficial-mirror/spice__spice-common,freedesktop-unofficial-mirror/spice__spice-common,fgouget/spice-common,Fantu/spice-common,fgouget/spice-common,SPICE/spice-common,freedesktop-unofficial-mirror/spice__spice-common,Fantu/spice-common,fgouget/spice-common