[libnotify] notification: Fix documentation and transfer info for NotifyActionCallback

[Marco Trevisan <marcotrevi src gnome org>]

commit 4e40a460ce873eed0d67b833f09fc636fd7caa1c
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Tue Jun 7 03:18:08 2022 +0200

    notification: Fix documentation and transfer info for NotifyActionCallback

 libnotify/notification.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/libnotify/notification.h b/libnotify/notification.h
index ffc960f..5706425 100644
--- a/libnotify/notification.h
+++ b/libnotify/notification.h
@@ -90,9 +90,9 @@ typedef enum
 
 /**
  * NotifyActionCallback:
- * @notification:
- * @action:
- * @user_data:
+ * @notification: a #NotifyActionCallback notification
+ * @action: (transfer none): The activated action name
+ * @user_data: (nullable) (transfer none): User provided data
  *
  * An action callback function.
  */