perf script: Use fallbacks for branch stacks

perf script: Use fallbacks for branch stacks

commit 692d0e63324d2954a0c63a812a8588e97023a295 upstream.

Branch stacks do not necessarily have the same cpumode as the 'ip'. Use
the fallback functions in those cases.

This patch depends on patch "perf tools: Add fallback functions for cases
where cpumode is insufficient".

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: stable@vger.kernel.org # 4.19
Link: http://lkml.kernel.org/r/20181106210712.12098-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>