perf_event_open.2: 4.1 PERF_SAMPLE_BRANCH_CALL_STACK

perf_event_open.2: 4.1 PERF_SAMPLE_BRANCH_CALL_STACK

This manpage patch relates to the addition of the
PERF_SAMPLE_BRANCH_CALL_STACK functionaliry added in the
following commit:

	commit 2c44b1936bb3b135a3fac8b3493394d42e51cf70
	Author: Peter Zijlstra <peterz@infradead.org>

	perf/x86/intel: Expose LBR callstack to user space tooling

	With LBR call stack feature enable, there are three callchain options.
	Enable the 3rd callchain option (LBR callstack) to user space tooling.

	Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
	Cc: Jiri Olsa <jolsa@redhat.com>
	Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
	Cc: Andy Lutomirski <luto@amacapital.net>
	Cc: Kan Liang <kan.liang@intel.com>
	Cc: Linus Torvalds <torvalds@linux-foundation.org>
	Cc: Paul Mackerras <paulus@samba.org>
	Cc: Vince Weaver <vincent.weaver@maine.edu>
	Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/20141105093759.GQ10501@worktop.programming.kicks-ass.net
	Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>