perf annotate: Factor out get/free_srcline()

Currently external addr2line tool is used for srcline sort key and
annotate with srcline info.  Separate the common code to prepare
upcoming enhancements.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1378876173-13363-5-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index e6fc38a..cca03831 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -535,7 +535,7 @@
 {
 	free(he->branch_info);
 	free(he->mem_info);
-	free(he->srcline);
+	free_srcline(he->srcline);
 	free(he);
 }