perf annotate: Use annotation__pcnt_width() consistently

perf annotate: Use annotation__pcnt_width() consistently

The annotation__pcnt_width() calculates the screen width for the
overhead (percent) area considering event groups properly.  Use this
function consistently so that we can make sure it has similar output
in different modes.  But there's a difference in stdio and tui output:
stdio uses 8 and tui uses 7 for a percent.

Let's use 8 and adjust the print width in __annotation_line__write()
properly.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240803211332.1107222-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>