The kbuild test robot reported a compile error if HIST_TRIGGERS was
enabled but nothing else that selected TRACING was configured in.

HIST_TRIGGERS should directly select it and not rely on anything else
to do it.

Link: http://lkml.kernel.org/r/57791866.8080505@linux.intel.comReported-by: Nkbuild test robot <fennguang.wu@intel.com>
Fixes: 7ef224d1 ("tracing: Add 'hist' event trigger command")
Signed-off-by: NTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>