vhost: simplify vhost_dev_init() fail_busyloop label

Requiring a conditional for every goto is tedious:

  if (busyloop_timeout) {
      goto fail_busyloop;
  } else {
      goto fail;
  }

Move the conditional to into the fail_busyloop label so that it's safe
to jump to this label unconditionally.

This change makes the migrate_add_blocker() error case more consistent.
It jumped to fail_busyloop unconditionally whereas the memslots limits
error case was conditional.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210222114931.272308-1-stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Author: stefanhaRH

hw/virtio/vhost.c

@@ -1388,18 +1388,16 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
         error_report("vhost backend memory slots limit is less"
                 " than current number of present memory slots");
         r = -1;
-        if (busyloop_timeout) {
-            goto fail_busyloop;
-        } else {
-            goto fail;
-        }
+        goto fail_busyloop;
     }
 
     return 0;
 
 fail_busyloop:
-    while (--i >= 0) {
-        vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
+    if (busyloop_timeout) {
+        while (--i >= 0) {
+            vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
+        }
     }
 fail:
     hdev->nvqs = n_initialized_vqs;