[PATCH 1/2] of/unittest: Remove test devices after adding them

The of_platform_populate() test cases don't remove the test devices after they are added. Fix this by adding tests for of_platform_depopulate(). At the same time rework the selftest() macro to return the test result value. This makes it easy to use the macro inside an if() condition.

[PATCH 1/2] of/unittest: Remove test devices after adding them

The of_platform_populate() test cases don't remove the test devices after they are added. Fix this by adding tests for of_platform_depopulate(). At the same time rework the selftest() macro to return the test result value. This makes it easy to use the macro inside an if() condition.