No need to make the user login here, and fix incorrect userid

Setting up FS is enough to get the correct file version. No need
to make the user login here.

File version would be in owner's FS, not editor, so
s/editorid/ownerid/

controller/documentcontroller.php

@@ -469,23 +469,11 @@ class DocumentController extends Controller {
 		if ($version !== '0') {
 			\OCP\JSON::checkAppEnabled('files_versions');
 
-			// Login as this user
-			$editorid = $res['editor'];
-			$users = \OC::$server->getUserManager()->search($editorid, 1, 0);
-			if (count($users) > 0)
-			{
-				$user = array_shift($users);
-				if (strcasecmp($user->getUID(),$editorid) === 0)
-				{
-					\OC::$server->getUserSession()->setUser($user);
-				}
-			}
-
-			\OCP\JSON::checkLoggedIn();
+			$ownerid = $res['owner'];
 
 			// Setup the FS
 			\OC_Util::tearDownFS();
-			\OC_Util::setupFS($editorid, '/' . $editorid . '/files');
+			\OC_Util::setupFS($ownerid, '/' . $ownerid . '/files');
 
 			list($owner_uid, $filename) = \OCA\Files_Versions\Storage::getUidAndFilename($res['path']);
 			$versionName = '/files_versions/' . $filename . '.v' . $version;