Use zalloc instead of calloc(1, ...)

Signed-off-by: Bryce Harrington <bryce@osg.samsung.com>
Reviewed-by: Marek Chalupa <mchqwerty@gmail.com>
diff --git a/src/vaapi-recorder.c b/src/vaapi-recorder.c
index 921494d..a469391 100644
--- a/src/vaapi-recorder.c
+++ b/src/vaapi-recorder.c
@@ -951,8 +951,8 @@
 	int major, minor;
 	int flags;
 
-	r = calloc(1, sizeof *r);
-	if (!r)
+	r = zalloc(sizeof *r);
+	if (r == NULL)
 		return NULL;
 
 	r->width = width;