terminal: enable sessions in evcat after taking control

If we enable a session, any probed device might get immediately enabled.
This might cause TakeDevice() messages to be sent before we call
TakeControl(). Therefore, enable sessions *after* sending TakeControl() so
we always succeed if TakeControl() succeeds.

src/libsystemd-terminal/evcat.c

@@ -313,8 +313,6 @@ static int evcat_sysview_fn(sysview_context *c, void *userdata, sysview_event *e
                         return r;
                 }
 
-                idev_session_enable(e->idev_session);
-
                 if (e->managed) {
                         r = sysview_session_take_control(ev->session_add.session);
                         if (r < 0) {
@@ -323,6 +321,8 @@ static int evcat_sysview_fn(sysview_context *c, void *userdata, sysview_event *e
                         }
                 }
 
+                idev_session_enable(e->idev_session);
+
                 break;
         case SYSVIEW_EVENT_SESSION_REMOVE:
                 idev_session_disable(e->idev_session);