perf tools: Move symbol__calc_percent() call to outside symbol__disassemble()

perf tools: Move symbol__calc_percent() call to outside symbol__disassemble()

We need to call symbol__calc_percent() periodicaly for top, so it's no
longer convenient to keep it in symbol__disassemble().

Let's separate the symbol__disassemble() to allocate and init
the symbol annotation structs and symbol__calc_percent() to
compute the lines percentages based on symbol hists data.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-gtnp8t4tb00q6lag07psn5nq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>