bitbake: runqueue: Fix setscene issues with multiconfig

bitbake: runqueue: Fix setscene issues with multiconfig

setscene was being entirelu skipped for multiconfig variants as the tasks
were simply not being spotted. If the default config was also being built
it masked the problem. When this was fixed by using taskfn instead of fn
in lookups against dataCache, several other instances of this problem were
highlighted.

This goes through and corrects the setscene code to correclty use taskfn
instead of fn in the appropriate places meaning setscene tasks for multiconfig
now work correctly.

(Bitbake rev: cead85cf219c07b40aeb7c0d948c25f0429136db)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>