Tests: remove "wait" in cleanupTestCase

For SpinBox and TableView testcases.

This function has been copied from other tests but
it was probably a hack to work around an old bug.

This should not be needed so removing it.

Change-Id: I0b9f6620fdc89a8f2125cf9bc9412cb45b21b500
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@digia.com>