[gdk-pixbuf] docs: Add missing argument

[Emmanuele Bassi <ebassi src gnome org>]

commit 3a68016b3ff662db1196c3f743e81ef06003394b
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Wed Aug 14 13:53:55 2019 +0100

    docs: Add missing argument

 gdk-pixbuf/gdk-pixbuf-io.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gdk-pixbuf/gdk-pixbuf-io.c b/gdk-pixbuf/gdk-pixbuf-io.c
index f5a9f953e..17ceb59df 100644
--- a/gdk-pixbuf/gdk-pixbuf-io.c
+++ b/gdk-pixbuf/gdk-pixbuf-io.c
@@ -570,6 +570,7 @@ gdk_pixbuf_io_init_modules (const char  *filename,
 /**
  * gdk_pixbuf_init_modules:
  * @path: Path to directory where the loaders.cache is installed
+ * @error: return location for a #GError
  *
  * Initalizes the gdk-pixbuf loader modules referenced by the loaders.cache
  * file present inside that directory.