tools/bootconfig: Show whole test command for each test case

Show whole test command instead of only the 3rd argument.
This will clear to show what will be actually tested by
each test case.

Link: https://lkml.kernel.org/r/163077088607.222577.14786016266462495017.stgit@devnote2

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