perf annotate: Fix missing branch counter column in TUI mode

perf annotate: Fix missing branch counter column in TUI mode

'perf annotate' checks that evlist->nr_br_cntr has been incremented to
determine whether to show branch counter information.

However, this data is not populated until after the check when events
are processed.

Therefore, this counter will always be less than zero and the Branch
Count column is never shown. Do this check after events have been
processed and branch counter data is updated.

Reviewed-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Thomas Falcon <thomas.falcon@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>