lisa.tests.staging.schedutil: Use cls.run_rtapp() instead of _run_rtapp()
lisa.tests.staging.schedutil: Use cls.run_rtapp() instead of _run_rtapp()

_run_rtapp() has been renamed a while ago into run_rtapp(), so use the new name.

credp/lisa,credp/lisa,credp/lisa,ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,ARM-software/lisa,credp/lisa