[glib] tests: Fix a typo on a dereferencing assignment

[Philip Withnall <pwithnall src gnome org>]

commit 5cdf0efaabb612908a08105b3a1826380c785234
Author: Philip Withnall <philip withnall collabora co uk>
Date:   Sat Aug 13 10:24:23 2016 +0200

    tests: Fix a typo on a dereferencing assignment
    
    Otherwise the assignment is pointless. Spotted by cppcheck.

 gio/tests/gdbus-peer.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gio/tests/gdbus-peer.c b/gio/tests/gdbus-peer.c
index 841c40c..081eef6 100644
--- a/gio/tests/gdbus-peer.c
+++ b/gio/tests/gdbus-peer.c
@@ -646,7 +646,7 @@ read_all_from_fd (gint fd, gsize *out_len, GError **error)
 
  error:
   if (out_len != NULL)
-    out_len = 0;
+    *out_len = 0;
   g_string_free (str, TRUE);
   return NULL;
 }