perf machine: Pass buffer size to machine__mmap_name

Don't blindly assume that the size of the buffer is enough, use
snprintf.

Cc: Avi Kivity <avi@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Zhang, Yanmin <yanmin_zhang@linux.intel.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index dc04636..c9c0bdd 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -1856,7 +1856,7 @@
 out_try_fixup:
 	if (err > 0) {
 		if (kallsyms_filename != NULL) {
-			machine__mmap_name(machine, path);
+			machine__mmap_name(machine, path, sizeof(path));
 			dso__set_long_name(self, strdup(path));
 		}
 		map__fixup_start(map);
@@ -1961,8 +1961,8 @@
 static struct dso *dso__new_guest_kernel(struct machine *machine,
 					const char *name)
 {
-	char buff[PATH_MAX];
-	struct dso *self = dso__new(name ?: machine__mmap_name(machine, buff));
+	char bf[PATH_MAX];
+	struct dso *self = dso__new(name ?: machine__mmap_name(machine, bf, sizeof(bf)));
 
 	if (self != NULL) {
 		dso__set_short_name(self, "[guest.kernel]");