[libgit2-glib] Update ggit_repository_submodule_foreach documentation

[Jesse van den Kieboom <jessevdk src gnome org>]

commit 6d108f1c8fade923ffc90e888b78a80c86d98843
Author: Jesse van den Kieboom <jessevdk gnome org>
Date:   Sat Aug 1 13:39:10 2015 +0200

    Update ggit_repository_submodule_foreach documentation

 libgit2-glib/ggit-repository.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)
---
diff --git a/libgit2-glib/ggit-repository.c b/libgit2-glib/ggit-repository.c
index 02c0ebb..6596a12 100644
--- a/libgit2-glib/ggit-repository.c
+++ b/libgit2-glib/ggit-repository.c
@@ -2021,11 +2021,15 @@ submodule_wrapper_callback (git_submodule *submodule,
  * @user_data: callback user data.
  * @error: a #GError for error reporting, or %NULL.
  *
- * Gathers file statuses and run a callback for each one.
+ * Gathers submodules and run a callback for each one.
  *
- * To the callback is passed the path of the file, the status and the data pointer
- * passed to this function. If the callback returns something other than
- * 0, the iteration will stop and @error will be set.
+ * To the callback is passed the submodule instance and name. If the callback
+ * returns something other than 0, the iteration will stop and @error
+ * will be set.
+ *
+ * NOTE: the submodule instance passed to the callback is only valid during
+ * the call to ggit_repository_submodule_foreach and may not be used after the
+ * call has finished.
  *
  * Returns: %TRUE if there was no error, %FALSE otherwise
  */