virtio_balloon: Adjust label in virtballoon_probe

Clang warns when CONFIG_BALLOON_COMPACTION is unset:

../drivers/virtio/virtio_balloon.c:963:1: warning: unused label
'out_del_vqs' [-Wunused-label]
out_del_vqs:
^~~~~~~~~~~~
1 warning generated.

Move the label within the preprocessor block since it is only used when
CONFIG_BALLOON_COMPACTION is set.

Fixes: 1ad6f58ea9 ("virtio_balloon: Fix memory leaks on errors in virtballoon_probe()")
Link: https://github.com/ClangBuiltLinux/linux/issues/886
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://lore.kernel.org/r/20200216004039.23464-1-natechancellor@gmail.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>

drivers/virtio/virtio_balloon.c

@@ -959,8 +959,8 @@ out_iput:
 	iput(vb->vb_dev_info.inode);
 out_kern_unmount:
 	kern_unmount(balloon_mnt);
-#endif
 out_del_vqs:
+#endif
 	vdev->config->del_vqs(vdev);
 out_free_vb:
 	kfree(vb);