virtio-mem: drop last_mb_id

No longer used, let's drop it.
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/20201112133815.13332-15-david@redhat.comSigned-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/virtio/virtio_mem.c

@@ -84,8 +84,6 @@ struct virtio_mem {
 
 	/* Id of the first memory block of this device. */
 	unsigned long first_mb_id;
-	/* Id of the last memory block of this device. */
-	unsigned long last_mb_id;
 	/* Id of the last usable memory block of this device. */
 	unsigned long last_usable_mb_id;
 	/* Id of the next memory bock to prepare when needed. */
@@ -1773,8 +1771,6 @@ static int virtio_mem_init(struct virtio_mem *vm)
 	vm->first_mb_id = virtio_mem_phys_to_mb_id(vm->addr - 1 +
 						   memory_block_size_bytes());
 	vm->next_mb_id = vm->first_mb_id;
-	vm->last_mb_id = virtio_mem_phys_to_mb_id(vm->addr +
-			 vm->region_size) - 1;
 
 	dev_info(&vm->vdev->dev, "start address: 0x%llx", vm->addr);
 	dev_info(&vm->vdev->dev, "region size: 0x%llx", vm->region_size);