[mutter] backends/native: Fix double free of error

[Jonas Ådahl <jadahl src gnome org>]

commit d70ddc65ea923d14dfa8f5b1f486455e6b6234b6
Author: Tim Crawford <tcrawford system76 com>
Date:   Fri Dec 6 11:23:54 2019 -0700

    backends/native: Fix double free of error
    
    error is an autoptr, so must not be explicitly freed.
    
    Fixes: https://gitlab.gnome.org/GNOME/gnome-shell/issues/1852
    Fixes: 5c500ad402194 ("backend: Move GPU ownership from the monitor manager to the backend")
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/960

 src/backends/native/meta-backend-native.c | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/src/backends/native/meta-backend-native.c b/src/backends/native/meta-backend-native.c
index 48bb7cabd..5e4a8dd97 100644
--- a/src/backends/native/meta-backend-native.c
+++ b/src/backends/native/meta-backend-native.c
@@ -583,7 +583,6 @@ on_udev_device_added (MetaUdev          *udev,
     {
       g_warning ("Failed to hotplug secondary gpu '%s': %s",
                  device_path, error->message);
-      g_error_free (error);
       return;
     }