[PATCH] baum: Fix crash when Braille output is not available

[Samuel Thibault]

When Braille output is not available, the backend properly reports being
unable to be created, but 5f8e93c3e262 ("util/qemu-timer: Make timer_free()
imply timer_del()") made the timer_free() call now refuse any NULL
parameter. char_braille_finalize thus now has to be more careful with
calling it on baum->cellCount_timer.

Signed-off-by: Samuel Thibault <samuel.thiba...@ens-lyon.org>
---
 chardev/baum.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/chardev/baum.c b/chardev/baum.c
index 5deca778bc..aca5bf12fb 100644
--- a/chardev/baum.c
+++ b/chardev/baum.c
@@ -631,7 +631,9 @@ static void char_braille_finalize(Object *obj)
 {
     BaumChardev *baum = BAUM_CHARDEV(obj);
 
-    timer_free(baum->cellCount_timer);
+    if (baum->cellCount_timer) {
+        timer_free(baum->cellCount_timer);
+    }
     if (baum->brlapi) {
         brlapi__closeConnection(baum->brlapi);
         g_free(baum->brlapi);
-- 
2.30.1