fix lock unlock - WlSessionLock.unlock() is a private slot, not QML-callable

modules/lock/LockAuth.qml

@@ -13,6 +13,7 @@ QtObject {
     property string message: ""
     property string buffer: ""
 
+    signal unlockRequested
     signal authFailed
 
     function submit() {
@@ -42,7 +43,7 @@ QtObject {
             if (res === PamResult.Success) {
                 root.state = "";
                 root.message = "";
-                root.lock.unlock();
+                root.unlockRequested();
                 return;
             }
 

modules/lock/LockSurface.qml

@@ -186,9 +186,9 @@ WlSessionLockSurface {
     property bool _unlocking: false
 
     Connections {
-        target: root.lock
+        target: root.auth
 
-        function onUnlock() {
+        function onUnlockRequested() {
             root._unlocking = true;
             _unlockAnim.start();
         }