ftracetest: Add --verbose option for showing echo output

Add --verbose/-v option for showing echo output in testcases.
This is good for checking the progress of testcases which
take a longer time to run.

To implement this feature, all the testcase failures are
captured in ftracetest and send signal to set SIG_RESULT=FAIL.

Link: http://lkml.kernel.org/r/20141204194123.7376.22964.stgit@localhost.localdomain
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>