tools/bootconfig: Add a summary of test cases and return error

Add summary lines of test cases and return an error
code if any test case fails so that tester don't have
to monitor the output.

Link: https://lkml.kernel.org/r/158898590533.22749.10269622752797822320.stgit@devnote2



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