drm/nouveau: Fix reference count leak in nouveau_connector_detect

[ Upstream commit 990a1162 ]

nouveau_connector_detect() calls pm_runtime_get_sync and in turn
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/gpu/drm/nouveau/nouveau_connector.c

@@ -551,8 +551,10 @@ nouveau_connector_detect(struct drm_connector *connector, bool force)
 		pm_runtime_get_noresume(dev->dev);
 	} else {
 		ret = pm_runtime_get_sync(dev->dev);
-		if (ret < 0 && ret != -EACCES)
+		if (ret < 0 && ret != -EACCES) {
+			pm_runtime_put_autosuspend(dev->dev);
 			return conn_status;
+		}
 	}
 
 	nv_encoder = nouveau_connector_ddc_detect(connector);