[gtk+] Fix a doc comment

[Matthias Clasen <matthiasc src gnome org>]

commit 9711608ba3b711dd50bac005f34d6fd1c5e95ea5
Author: Matthias Clasen <mclasen redhat com>
Date:   Wed Aug 5 14:20:00 2015 -0400

    Fix a doc comment

 gtk/gtkstack.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gtk/gtkstack.c b/gtk/gtkstack.c
index 56dc3cf..ce5486c 100644
--- a/gtk/gtkstack.c
+++ b/gtk/gtkstack.c
@@ -1646,6 +1646,7 @@ gtk_stack_get_transition_running (GtkStack *stack)
 /**
  * gtk_stack_set_interpolate_size:
  * @stack: A #GtkStack
+ * @interpole_size: the new value
  *
  * Sets whether or not @stack will interpolate its size when
  * changing the visible child. If the interpolate-size property