kunit: test: improve error messages for invalid kconfigs

Was trying to port an existing kunitconfig to the alpha branch and found
the error pretty opaque:

	$ ./tools/testing/kunit/kunit.py run --raw_output
	Regenerating .config ...
	ERROR:root:Provided Kconfig is not contained in validated .config!

Include the missing fields in the error message:

	$ ./tools/testing/kunit/kunit.py run --raw_output
	Regenerating .config ...
	ERROR:root:Provided Kconfig contains fields not in validated
	.config: CONFIG_KUNIT=y, CONFIG_KUNIT_TEST=y,
	CONFIG_KUNIT_EXAMPLE_TEST=y

Signed-off-by: Eric Chiang <ericchiang@google.com>
Change-Id: I04bf8cff499fd3e548a6a8da7ff3ea65e44a0161
1 file changed