First, why doing git init, and where? I would understand a git submodule init.
Second, as mentioned in the comments of "Rename a git submodule":
.gitmodules contains no absolute path information.
However {submodule}/.git and .git/modules/submodules/{submodule}/config do
So check the content of the ResKit/.git/config and see if there is a path that needs to be updated.
Or try and do a git deinit ResKit, followed by a git submodule update --init
Or do the manual version of the previous process: delete .git/modules/submodules/ResKit, and try again git submodule update --init