drm/stm: Replace drm_dev_unref with drm_dev_put

This patch unifies the naming of DRM functions for reference counting
of struct drm_device. The resulting code is more aligned with the rest
of the Linux kernel interfaces.
Signed-off-by: NThomas Zimmermann <tzimmermann@suse.de>
Acked-by: NPhilippe Cornu <philippe.cornu@st.com>
Signed-off-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180713080625.18256-1-tzimmermann@suse.de

drivers/gpu/drm/stm/drv.c

@@ -148,16 +148,16 @@ static int stm_drm_platform_probe(struct platform_device *pdev)
 
 	ret = drv_load(ddev);
 	if (ret)
-		goto err_unref;
+		goto err_put;
 
 	ret = drm_dev_register(ddev, 0);
 	if (ret)
-		goto err_unref;
+		goto err_put;
 
 	return 0;
 
-err_unref:
-	drm_dev_unref(ddev);
+err_put:
+	drm_dev_put(ddev);
 
 	return ret;
 }
@@ -170,7 +170,7 @@ static int stm_drm_platform_remove(struct platform_device *pdev)
 
 	drm_dev_unregister(ddev);
 	drv_unload(ddev);
-	drm_dev_unref(ddev);
+	drm_dev_put(ddev);
 
 	return 0;
 }