[gnome-power-manager] Initialize the error before using in gpm_backlight_dbus_method_call(). Fixes rh#676075

[Richard Hughes <rhughes src gnome org>]

commit b7567003fef441468cd49eb36a56a5d3f35e1166
Author: Richard Hughes <richard hughsie com>
Date:   Wed Feb 9 09:20:20 2011 +0000

    Initialize the error before using in gpm_backlight_dbus_method_call(). Fixes rh#676075

 src/gpm-backlight.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/gpm-backlight.c b/src/gpm-backlight.c
index e27172e..49ae9e1 100644
--- a/src/gpm-backlight.c
+++ b/src/gpm-backlight.c
@@ -682,7 +682,7 @@ gpm_backlight_dbus_method_call (GDBusConnection *connection,
 				GVariant *parameters, GDBusMethodInvocation *invocation,
 				gpointer user_data)
 {
-	GError *error;
+	GError *error = NULL;
 	guint value;
 	gboolean ret;
 	GpmBacklight *backlight = GPM_BACKLIGHT (user_data);