Assertions for Flexelint

It could infer that the result of a non-NULL cast of task->priv can not
be null, but it doesn't. Sigh.

src/vmod_re.c

@@ -164,7 +164,7 @@ match(VRT_CTX, vre_t *vre, VCL_STRING subject, struct vmod_priv *task,
 	}
 	else {
 		WS_Assert_Allocated(ctx->ws, task->priv, sizeof(*ov));
-		CAST_OBJ(ov, task->priv, OV_MAGIC);
+		CAST_OBJ_NOTNULL(ov, task->priv, OV_MAGIC);
 	}
 
 	len = strlen(subject);
@@ -218,7 +218,7 @@ backref(VRT_CTX, VCL_INT refnum, VCL_STRING fallback, struct vmod_priv *task)
 		return fallback;
 
 	WS_Assert_Allocated(ctx->ws, task->priv, sizeof(*ov));
-	CAST_OBJ(ov, task->priv, OV_MAGIC);
+	CAST_OBJ_NOTNULL(ov, task->priv, OV_MAGIC);
 
 	refnum <<= 1;
 	assert(refnum + 1 < MAX_OV_USED);