drm: Add missing mutex_destroy in drm_dev_init/release

Add 3 missing mutex_destroy to drm_dev_init teardown and
drm_dev_release.

v2:
- Also include drm_dev_release

Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1478785835-4142-1-git-send-email-joonas.lahtinen@linux.intel.com
Link: http://patchwork.freedesktop.org/patch/msgid/1478785835-4142-1-git-send-email-joonas.lahtinen@linux.intel.com

drivers/gpu/drm/drm_drv.c

@@ -568,6 +568,9 @@ err_minors:
 	drm_fs_inode_free(dev->anon_inode);
 err_free:
 	mutex_destroy(&dev->master_mutex);
+	mutex_destroy(&dev->ctxlist_mutex);
+	mutex_destroy(&dev->filelist_mutex);
+	mutex_destroy(&dev->struct_mutex);
 	return ret;
 }
 EXPORT_SYMBOL(drm_dev_init);
@@ -630,6 +633,9 @@ static void drm_dev_release(struct kref *ref)
 	drm_minor_free(dev, DRM_MINOR_CONTROL);
 
 	mutex_destroy(&dev->master_mutex);
+	mutex_destroy(&dev->ctxlist_mutex);
+	mutex_destroy(&dev->filelist_mutex);
+	mutex_destroy(&dev->struct_mutex);
 	kfree(dev->unique);
 	kfree(dev);
 }