perf annotate: Find 'call' instruction target symbol at parsing time

So that we do it just once, not everytime we press enter or -> on a
'call' instruction line.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.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-uysyojl1e6nm94amzzzs08tf@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/annotate.h

@@ -24,6 +24,7 @@ struct ins_operands {
 	struct {
 		char	*raw;
 		char	*name;
+		struct symbol *sym;
 		u64	addr;
 		s64	offset;
 		bool	offset_avail;