fix waffle instance module name
fix waffle instance module name

Fixes the computation of the WaffleFlag and
WaffleSwitch instance module name. This in
turn fixes the code_owner as well.

ARCHBOM-1420

arbrandes/edx-platform,edx/edx-platform,EDUlib/edx-platform,edx/edx-platform,arbrandes/edx-platform,arbrandes/edx-platform,angelapper/edx-platform,eduNEXT/edx-platform,EDUlib/edx-platform,angelapper/edx-platform,eduNEXT/edunext-platform,eduNEXT/edx-platform,eduNEXT/edunext-platform,stvstnfrd/edx-platform,stvstnfrd/edx-platform,edx/edx-platform,edx/edx-platform,stvstnfrd/edx-platform,eduNEXT/edunext-platform,EDUlib/edx-platform,eduNEXT/edunext-platform,EDUlib/edx-platform,eduNEXT/edx-platform,eduNEXT/edx-platform,angelapper/edx-platform,arbrandes/edx-platform,angelapper/edx-platform,stvstnfrd/edx-platform