Give VDP a proper VDP_Init() function

bin/varnishd/cache/cache_deliver_proc.c

@@ -34,6 +34,13 @@
 #include "cache_varnishd.h"
 #include "cache_filter.h"
 
+void
+VDP_Init(struct vdp_ctx *vdx)
+{
+	INIT_OBJ(vdx, VDP_CTX_MAGIC);
+	VTAILQ_INIT(&vdx->vdp);
+}
+
 /* VDP_bytes
  *
  * Pushes len bytes at ptr down the delivery processor list.
@@ -57,6 +64,7 @@
  * r == 0: Continue
  * r > 0:  Stop, breaks out early without error condition
  */
+
 int
 VDP_bytes(struct vdp_ctx *vdx, enum vdp_action act, const void *ptr, ssize_t len)
 {

bin/varnishd/cache/cache_filter.h

@@ -148,6 +148,7 @@ struct vdp_ctx {
 	struct req		*req;
 };
 
+void VDP_Init(struct vdp_ctx *vdx);
 int VDP_bytes(struct vdp_ctx *, enum vdp_action act, const void *ptr, ssize_t len);
 int VDP_Push(struct req *, const struct vdp *, void *priv);
 void VRT_AddVDP(VRT_CTX, const struct vdp *);

bin/varnishd/cache/cache_req.c

@@ -131,8 +131,7 @@ Req_New(const struct worker *wrk, struct sess *sp)
 	p = (void*)PRNDUP(p + sizeof(*req->htc));
 
 	req->vdc = (void*)p;
-	INIT_OBJ(req->vdc, VDP_CTX_MAGIC);
-	VTAILQ_INIT(&req->vdc->vdp);
+	VDP_Init(req->vdc);
 	p = (void*)PRNDUP(p + sizeof(*req->vdc));
 
 	req->htc = (void*)p;