tracepoint: Use static_key_false(), since static_branch() is deprecated

Convert the last user of static_branch() -> static_key_false().

Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: a.p.zijlstra@chello.nl
Link: http://lkml.kernel.org/r/5fffcd40a6c063769badcdd74a7d90980500dbcb.1340909155.git.jbaron@redhat.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>