perf tools: Introduce zalloc() for the common calloc(1, N) case

This way we type less characters and it looks more like the
kzalloc kernel counterpart.

Signed-off-by: Arnaldo Carvalho de Melo <acme@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>
LKML-Reference: <1259071517-3242-3-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/tools/perf/util/header.c b/tools/perf/util/header.c
index 271a160..4b58656 100644
--- a/tools/perf/util/header.c
+++ b/tools/perf/util/header.c
@@ -63,7 +63,7 @@
  */
 struct perf_header *perf_header__new(void)
 {
-	struct perf_header *self = calloc(sizeof(*self), 1);
+	struct perf_header *self = zalloc(sizeof(*self));
 
 	if (self != NULL) {
 		self->size = 1;