Use calloc() instead of malloc + memset

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/iolog.c b/iolog.c
index ef8b841..cfcab27 100644
--- a/iolog.c
+++ b/iolog.c
@@ -539,9 +539,9 @@
 void setup_log(struct io_log **log, struct log_params *p,
 	       const char *filename)
 {
-	struct io_log *l = malloc(sizeof(*l));
+	struct io_log *l;
 
-	memset(l, 0, sizeof(*l));
+	l = calloc(1, sizeof(*l));
 	l->nr_samples = 0;
 	l->max_samples = 1024;
 	l->log_type = p->log_type;