selftests/ftrace: Cleanup ftrace after running test

Cleanup ftrace by initialize_ftrace() after running
all test cases. This means we also don't need cleanup
ftrace on each test case, except for some special
options.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>

tools/testing/selftests/ftrace/ftracetest

@@ -341,6 +341,7 @@ for t in $TEST_CASES; do
     exit 1
   fi
 done
+(cd $TRACING_DIR; initialize_ftrace) # for cleanup
 
 prlog ""
 prlog "# of passed: " `echo $PASSED_CASES | wc -w`