[libgsystem] subprocess: Fix a potential GCancellable leak

[Philip Withnall <pwithnall src gnome org>]

commit b46bc1002ea3a1282708e6c482cb2594af3162a0
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Mon Oct 27 13:29:16 2014 +0000

    subprocess: Fix a potential GCancellable leak

 src/gsystem-subprocess.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/gsystem-subprocess.c b/src/gsystem-subprocess.c
index 4ec680f..0248072 100644
--- a/src/gsystem-subprocess.c
+++ b/src/gsystem-subprocess.c
@@ -599,6 +599,7 @@ gs_subprocess_on_child_exited (GPid       pid,
 
   g_simple_async_result_complete (data->result);
 
+  g_clear_object (&data->cancellable);
   g_object_unref (data->result);
   g_object_unref (data->self);
   g_free (data);