smalloc: add zeroing scalloc() variant

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/smalloc.c b/smalloc.c
index 5fe0b6f..1ba9353 100644
--- a/smalloc.c
+++ b/smalloc.c
@@ -479,6 +479,17 @@
 	return NULL;
 }
 
+void *scalloc(size_t nmemb, size_t size)
+{
+	void *ret;
+
+	ret = smalloc(nmemb * size);
+	if (ret)
+		memset(ret, 0, nmemb * size);
+
+	return ret;
+}
+
 char *smalloc_strdup(const char *str)
 {
 	char *ptr;