perf tools: Use SBUILD_ID_SIZE where applicable

Use the existing SBUILD_ID_SIZE macro instead of the equivalent
BUILD_ID_SIZE * 2 + 1 expression for allocating a buffer for build-id
strings.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160511135159.23943.57120.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 8e639543..3357479 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -38,7 +38,7 @@
 				   enum dso_binary_type type,
 				   char *root_dir, char *filename, size_t size)
 {
-	char build_id_hex[BUILD_ID_SIZE * 2 + 1];
+	char build_id_hex[SBUILD_ID_SIZE];
 	int ret = 0;
 	size_t len;
 
@@ -1301,7 +1301,7 @@
 
 size_t dso__fprintf_buildid(struct dso *dso, FILE *fp)
 {
-	char sbuild_id[BUILD_ID_SIZE * 2 + 1];
+	char sbuild_id[SBUILD_ID_SIZE];
 
 	build_id__sprintf(dso->build_id, sizeof(dso->build_id), sbuild_id);
 	return fprintf(fp, "%s", sbuild_id);