selftests: ftrace: Shift down default message verbosity

Shift down default message verbosity, where it does not show
error results in stdout by default. Since that behavior
is the same as giving the --quiet option, this patch removes
--quiet and makes --verbose increasing verbosity.

In other words, this changes verbosity options as below.
ftracetest -q -> ftracetest
ftracetest    -> ftracetest -v
ftracetest -v -> ftracetest -v -v (or -vv)

Link: http://lkml.kernel.org/r/148007872763.5917.15256235993753860592.stgit@devbox



Acked-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>