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/symbol.c b/tools/perf/util/symbol.c
index c4ca974..8db85b4 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -94,15 +94,14 @@
 static struct symbol *symbol__new(u64 start, u64 len, const char *name)
 {
 	size_t namelen = strlen(name) + 1;
-	struct symbol *self = calloc(1, (symbol__priv_size +
-					 sizeof(*self) + namelen));
-	if (!self)
+	struct symbol *self = zalloc(symbol__priv_size +
+				     sizeof(*self) + namelen);
+	if (self == NULL)
 		return NULL;
 
-	if (symbol__priv_size) {
-		memset(self, 0, symbol__priv_size);
+	if (symbol__priv_size)
 		self = ((void *)self) + symbol__priv_size;
-	}
+
 	self->start = start;
 	self->end   = len ? start + len - 1 : start;