bootconfig: Check the parsed output of the good examples

Check whether the parsed output of the good example configs are
the same as expected.

Link: https://lore.kernel.org/all/177025239529.14982.12913754615993262263.stgit@devnote2/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org>