vhost-user-scsi: add missing virtqueue_size param

Commit 5c0919d [1] introduced virtqueue_size parameter
for common virtio-scsi path, without updaing the vhost-user-scsi
code. vhost-user-scsi devices right now report size 0 for each vq.

This patch introduces virtqueue_size param to vhost-user-scsi,
that can now be set by the user. However, the most importantly, it
now has a default value of 128 (same as QEMU's virtio-scsi).

[1] 5c0919d ("virtio-scsi: Add virtqueue_size parameter
allowing virtqueue size to be set.")

Change-Id: I70e87eab702ebf1196c028dbf17d54fdc0c89a14
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Message-Id: <1510676916-76409-1-git-send-email-dariuszx.stojaczyk@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/scsi/vhost-user-scsi.c

@@ -135,6 +135,8 @@ static Property vhost_user_scsi_properties[] = {
     DEFINE_PROP_CHR("chardev", VirtIOSCSICommon, conf.chardev),
     DEFINE_PROP_UINT32("boot_tpgt", VirtIOSCSICommon, conf.boot_tpgt, 0),
     DEFINE_PROP_UINT32("num_queues", VirtIOSCSICommon, conf.num_queues, 1),
+    DEFINE_PROP_UINT32("virtqueue_size", VirtIOSCSICommon, conf.virtqueue_size,
+                       128),
     DEFINE_PROP_UINT32("max_sectors", VirtIOSCSICommon, conf.max_sectors,
                        0xFFFF),
     DEFINE_PROP_UINT32("cmd_per_lun", VirtIOSCSICommon, conf.cmd_per_lun, 128),