perf annotate --show-nr-samples does not really show number of samples.

The reason is we have two separate variables for the same purpose.

One is in symbol_conf.show_nr_samples and another is
annotation_options.show_nr_samples.

We save command line option in symbol_conf.show_nr_samples but uses
annotation_option.show_nr_samples while rendering tui/stdio2 browser.

Though, we copy symbol_conf.show_nr_samples to
annotation__default_options.show_nr_samples but that is not really
effective as we don't use annotation__default_options once we copy
default options to dynamic variable annotate.opts in cmd_annotate().

Instead of all these complication, keep only one variable and use it all
over. symbol_conf.show_nr_samples is used by perf report/top as well. So
let's kill annotation_options.show_nr_samples.

On a side note, I've kept annotation_options.show_nr_samples definition
because it's still used by perf-config code. Follow up patch to fix
perf-config for annotate will remove annotation_options.show_nr_samples.
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: Changbin Du <changbin.du@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yisheng Xie <xieyisheng1@huawei.com>
Link: http://lore.kernel.org/lkml/20200213064306.160480-4-ravi.bangoria@linux.ibm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>