[gdm] worker: don't use SIGUSR1 for VT switch signal

[Ray Strode <halfline src gnome org>]

commit 2b02aadfcd4aff9052e425e3292943e99320f4fc
Author: Ray Strode <rstrode redhat com>
Date:   Mon Mar 2 09:15:40 2015 -0500

    worker: don't use SIGUSR1 for VT switch signal
    
    That signal is blocked when the worker is forked,
    because the main daemon uses it to notice when
    the X server is ready.
    
    This commit changes the worker to use real-time
    signals instead, which are better anyway, since
    they queue.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745465

 daemon/gdm-session-worker.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index 5c88125..ccfa97e 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -106,8 +106,8 @@
 #define MAX_FILE_SIZE     65536
 #define MAX_LOGS          5
 
-#define RELEASE_DISPLAY_SIGNAL SIGUSR1
-#define ACQUIRE_DISPLAY_SIGNAL SIGUSR2
+#define RELEASE_DISPLAY_SIGNAL (SIGRTMAX)
+#define ACQUIRE_DISPLAY_SIGNAL (SIGRTMAX - 1)
 
 enum {
         GDM_SESSION_WORKER_STATE_NONE = 0,