vhost-user-blk: Make sure to set Error on realize failure

We have to set errp before jumping to virtio_err, otherwise the caller
(virtio_device_realize()) will take this as success and crash when it
later tries to access things that we've already freed in the error path.

Fixes: 77542d4
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210429171316.162022-2-kwolf@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

hw/block/vhost-user-blk.c

@@ -447,7 +447,6 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
 {
     VirtIODevice *vdev = VIRTIO_DEVICE(dev);
     VHostUserBlk *s = VHOST_USER_BLK(vdev);
-    Error *err = NULL;
     int i, ret;
 
     if (!s->chardev.chr) {
@@ -495,8 +494,7 @@ static void vhost_user_blk_device_realize(DeviceState *dev, Error **errp)
                              NULL, true);
 
 reconnect:
-    if (qemu_chr_fe_wait_connected(&s->chardev, &err) < 0) {
-        error_report_err(err);
+    if (qemu_chr_fe_wait_connected(&s->chardev, errp) < 0) {
         goto virtio_err;
     }