ftracetest: Add ftrace basic testcases

Add ftrace basic testcases. This just checks ftrace debugfs
interface works as it is designed.

Link: http://lkml.kernel.org/p/[e-mail]

Acked-by: Namhyung Kim <[e-mail]>
Signed-off-by: Masami Hiramatsu <[e-mail]>
Signed-off-by: Steven Rostedt <[e-mail]>

tools/testing/selftests/ftrace/test.d/00basic/basic1.tc

···
+#!/bin/sh
+# description: Basic trace file check
+test -f README -a -f trace -a -f tracing_on -a -f trace_pipe

tools/testing/selftests/ftrace/test.d/00basic/basic2.tc

···
+#!/bin/sh
+# description: Basic test for tracers
+for t in `cat available_tracers`; do
+  echo $t > current_tracer || exit 1
+done
+echo nop > current_tracer

tools/testing/selftests/ftrace/test.d/00basic/basic3.tc

···
+#!/bin/sh
+# description: Basic trace clock test
+[ -f trace_clock ] || exit 1
+for c in `cat trace_clock | tr  -d \[\]`; do
+  echo $c > trace_clock || exit 1
+  grep '\['$c'\]' trace_clock || exit 1
+done
+echo local > trace_clock