ftrace: add self-tests

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --cc kernel/trace/Kconfig
Simple merge

diff --cc kernel/trace/trace.c
Simple merge

diff --cc kernel/trace/trace.h
Simple merge

diff --cc kernel/trace/trace_functions.c
Simple merge

diff --cc kernel/trace/trace_irqsoff.c
Simple merge

diff --cc kernel/trace/trace_sched_switch.c
Simple merge

diff --cc kernel/trace/trace_sched_wakeup.c
Simple merge

diff --cc kernel/trace/trace_selftest.c
Simple merge