drm/nouveau: fix reference count leak in nouveau_debugfs_strap_peek

nouveau_debugfs_strap_peek() calls pm_runtime_get_sync() that
increments the reference count. In case of failure, decrement the
ref count before returning the error.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_debugfs.c

@@ -54,8 +54,10 @@ nouveau_debugfs_strap_peek(struct seq_file *m, void *data)
 	int ret;
 
 	ret = pm_runtime_get_sync(drm->dev->dev);
-	if (ret < 0 && ret != -EACCES)
+	if (ret < 0 && ret != -EACCES) {
+		pm_runtime_put_autosuspend(drm->dev->dev);
 		return ret;
+	}
 
 	seq_printf(m, "0x%08x\n",
 		   nvif_rd32(&drm->client.device.object, 0x101000));