fix ShowFolder tests in newfiles

we were trying to always call Router.Link.restore()
and getting this error:

Teardown failed on when collection is loaded and empty display no matches found:
[object Function] has no method 'restore'

Change-Id: I2f34ef0ae9da8baf3f84c7a4283347e98c47a971
Reviewed-on: https://gerrit.instructure.com/41231
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Clay Diffrient <cdiffrient@instructure.com>
Product-Review: Ryan Shaw <ryan@instructure.com>
QA-Review: Ryan Shaw <ryan@instructure.com>