[gdm] manager: fix crash if session fails to start

[Ray Strode <halfline src gnome org>]

commit 0ab4f635630cfd90b73cd138144999834d4d2c39
Author: Ray Strode <rstrode redhat com>
Date:   Mon Apr 17 13:07:48 2017 -0400

    manager: fix crash if session fails to start
    
    commit 5c9e120594839b0597bc7bb8d06be7ba1076c0d8 attempts to handle
    a session failing to start, but messages up the signal prototype
    leading to crash.
    
    This commit fixes that.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781413

 daemon/gdm-manager.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index b909976..b9b230a 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -1976,9 +1976,10 @@ remove_user_session (GdmManager *manager,
 static void
 on_session_start_failed (GdmSession *session,
                          const char *service_name,
+                         const char *message,
                          GdmManager *manager)
 {
-        g_debug ("GdmManager: session failed to start");
+        g_debug ("GdmManager: session failed to start: %s", message);
         remove_user_session (manager, session);
 }