drm/nouveau: Merge pre/postclose hooks

Again no apparent explanation for the split except hysterical raisins.
Merging them also makes it a bit more obviuos what's going on wrt the
runtime pm refdancing.

Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: nouveau@lists.freedesktop.org
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170508082633.4214-1-daniel.vetter@ffwll.ch

drivers/gpu/drm/nouveau/nouveau_drm.c

@@ -881,7 +881,7 @@ nouveau_drm_open(struct drm_device *dev, struct drm_file *fpriv)
 }
 
 static void
-nouveau_drm_preclose(struct drm_device *dev, struct drm_file *fpriv)
+nouveau_drm_postclose(struct drm_device *dev, struct drm_file *fpriv)
 {
 	struct nouveau_cli *cli = nouveau_cli(fpriv);
 	struct nouveau_drm *drm = nouveau_drm(dev);
@@ -897,12 +897,6 @@ nouveau_drm_preclose(struct drm_device *dev, struct drm_file *fpriv)
 	list_del(&cli->head);
 	mutex_unlock(&drm->client.mutex);
 
-}
-
-static void
-nouveau_drm_postclose(struct drm_device *dev, struct drm_file *fpriv)
-{
-	struct nouveau_cli *cli = nouveau_cli(fpriv);
 	nouveau_cli_fini(cli);
 	kfree(cli);
 	pm_runtime_mark_last_busy(dev->dev);
@@ -974,7 +968,6 @@ driver_stub = {
 	.load = nouveau_drm_load,
 	.unload = nouveau_drm_unload,
 	.open = nouveau_drm_open,
-	.preclose = nouveau_drm_preclose,
 	.postclose = nouveau_drm_postclose,
 	.lastclose = nouveau_vga_lastclose,