perf annotate: Move nr_jumps to struct annotation

perf annotate: Move nr_jumps to struct annotation

This is another information that will be useful for the --stdio2 mode,
to provide symbol statistics, so move it from the TUI and change the
mark_jump_targets() method to struct annotation.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-kpgle1qxe7thajvrqleuvi80@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>