[libadwaita] Make all set/get_icon_name functions nullable

[Alexander Mikhaylenko <alexm src gnome org>]

commit 6fe35c2c5a1ef32697f2cd9eed054a7998ebc67a
Author: Sophie Herold <sophie hemio de>
Date:   Mon Jul 5 17:38:21 2021 +0200

    Make all set/get_icon_name functions nullable

 src/adw-action-row.c   | 4 ++--
 src/adw-expander-row.c | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/src/adw-action-row.c b/src/adw-action-row.c
index f4822b0f..55863ecf 100644
--- a/src/adw-action-row.c
+++ b/src/adw-action-row.c
@@ -492,7 +492,7 @@ adw_action_row_set_subtitle (AdwActionRow *self,
  *
  * Gets the icon name for @self.
  *
- * Returns: the icon name for @self
+ * Returns: (nullable): the icon name for @self
  *
  * Since: 1.0
  */
@@ -511,7 +511,7 @@ adw_action_row_get_icon_name (AdwActionRow *self)
 /**
  * adw_action_row_set_icon_name: (attributes org.gtk.Method.set_property=icon-name)
  * @self: a `AdwActionRow`
- * @icon_name: the icon name
+ * @icon_name: (nullable): the icon name
  *
  * Sets the icon name for @self.
  *
diff --git a/src/adw-expander-row.c b/src/adw-expander-row.c
index 74b2ce5a..b4b40ec6 100644
--- a/src/adw-expander-row.c
+++ b/src/adw-expander-row.c
@@ -443,7 +443,7 @@ adw_expander_row_set_use_underline (AdwExpanderRow *self,
  *
  * Gets the icon name for @self.
  *
- * Returns: the icon name for @self
+ * Returns: (nullable): the icon name for @self
  *
  * Since: 1.0
  */
@@ -462,7 +462,7 @@ adw_expander_row_get_icon_name (AdwExpanderRow *self)
 /**
  * adw_expander_row_set_icon_name: (attributes org.gtk.Method.set_property=icon-name)
  * @self: a `AdwExpanderRow`
- * @icon_name: the icon name
+ * @icon_name: (nullable): the icon name
  *
  * Sets the icon name for @self.
  *