gpu: nvgpu: fix list_add_tail in dmabuf state

Fix a memory leak: add the newly created state to the dmabuf priv's
state list, instead of the other way around.

Bug 1594784
Bug 200064154

Change-Id: I939746a254bb8bf4d06de7fcecba06c191da665f
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: http://git-master/r/668758
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Lauri Peltonen <lpeltonen@nvidia.com>
Reviewed-by: Arto Merilainen <amerilainen@nvidia.com>

drivers/gpu/nvgpu/gk20a/mm_gk20a.c

@@ -2566,7 +2566,7 @@ int gk20a_dmabuf_get_state(struct dma_buf *dmabuf, struct device *dev,
 	s->offset = offset;
 	INIT_LIST_HEAD(&s->list);
 	mutex_init(&s->lock);
-	list_add_tail(&priv->states, &s->list);
+	list_add_tail(&s->list, &priv->states);
 
 out:
 	mutex_unlock(&priv->lock);