[gtk+] SpinButton: Explain meaning of nullable Adjustment

[Daniel Boles <dboles src gnome org>]

commit fecce75c73c4422cf244b619a0006a08b2d59c35
Author: Daniel Boles <dboles src gnome org>
Date:   Wed Nov 22 20:27:26 2017 +0000

    SpinButton: Explain meaning of nullable Adjustment
    
    configure() marked the @adj argument as (allow-none) but did not explain
    what passing NULL would do. Fix that, and move it to (nullable) as well.

 gtk/gtkspinbutton.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkspinbutton.c b/gtk/gtkspinbutton.c
index 7db7f54..7776c27 100644
--- a/gtk/gtkspinbutton.c
+++ b/gtk/gtkspinbutton.c
@@ -1531,13 +1531,13 @@ gtk_spin_button_default_output (GtkSpinButton *spin_button)
 /**
  * gtk_spin_button_configure:
  * @spin_button: a #GtkSpinButton
- * @adjustment: (allow-none):  a #GtkAdjustment
+ * @adjustment: (nullable): a #GtkAdjustment to replace the spin button’s
+ *     existing adjustment, or %NULL to leave its current adjustment unchanged
  * @climb_rate: the new climb rate
  * @digits: the number of decimal places to display in the spin button
  *
  * Changes the properties of an existing spin button. The adjustment,
- * climb rate, and number of decimal places are all changed accordingly,
- * after this function call.
+ * climb rate, and number of decimal places are updated accordingly.
  */
 void
 gtk_spin_button_configure (GtkSpinButton *spin_button,