Fix vrouter build for kernels from 4.11 to 4.13

- linux/vhost_dev.c:
  Rename netdev destructor to priv_destructor due to API change.
  New signature of rtnl_link_ops.validate due to API change.
- linux/vr_mem.c
  Remove vma from mem_fault function since VMA pointer now accessable
  via VMF structure.

Change-Id: I9ffc103e5e69649d2a691c7a378cfd12b2363320
Partial-Bug: #1633387

linux/vhost_dev.c

@@ -467,7 +467,12 @@ vhost_setup(struct net_device *dev)
 #endif
     dev->needed_headroom = sizeof(struct vr_eth) + sizeof(struct agent_hdr);
     dev->netdev_ops = &vhost_dev_ops;
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,11,9))
+    dev->priv_destructor = vhost_dev_destructor;
+    dev->needs_free_netdev = true;
+#else
     dev->destructor = vhost_dev_destructor;
+#endif /*KERNEL_4.11*/
 #ifdef CONFIG_XEN
     dev->ethtool_ops = &vhost_ethtool_ops;
     dev->features |= NETIF_F_GRO;
@@ -518,8 +523,15 @@ vhost_dellink(struct net_device *dev, struct list_head *head)
     return;
 }
 
+
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,13,0))
+static int
+vhost_validate(struct nlattr *tb[], struct nlattr *data[],
+    struct netlink_ext_ack *extack)
+#else
 static int
 vhost_validate(struct nlattr *tb[], struct nlattr *data[])
+#endif /*KERNEL_4.13*/
 {
     if (vhost_num_interfaces >= VHOST_MAX_INTERFACES)
         return -ENOMEM;
@@ -535,7 +547,6 @@ static struct rtnl_link_ops vhost_link_ops = {
     .dellink    =   vhost_dellink,
 };
 
-
 static void
 vhost_netlink_exit(void)
 {

linux/vr_mem.c

@@ -310,12 +310,19 @@ vr_huge_pages_init()
     return 0;
 }
 
-
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4,11,0))
 static int
 mem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 {
-    void *va;
     struct vr_mem_object *vmo = (struct vr_mem_object *)vma->vm_private_data;
+#else
+static int
+mem_fault(struct vm_fault *vmf)
+{
+    struct vr_mem_object *vmo =
+        (struct vr_mem_object *)vmf->vma->vm_private_data;
+#endif /*KERNEL_4.11*/
+    void *va;
     struct vrouter *router = vmo->vmo_router;
     struct page *page;
     pgoff_t offset;