[gtk+/gtk-3-22] TextView: Be const-correct when passing a pointer

[Daniel Boles <dboles src gnome org>]

commit 08887f0577eb8f38cdbfdd886adbf4d81af99bbe
Author: Daniel Boles <dboles src gnome org>
Date:   Mon Mar 27 19:14:38 2017 +0100

    TextView: Be const-correct when passing a pointer
    
    The TextIter is passed by pointer for efficiency. We neither need to
    modify it, nor should we leave it possible to accidentally do so. So,
    it should be passed as a pointer-to-const.

 gtk/gtktextview.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtktextview.c b/gtk/gtktextview.c
index 25d7616..b675d35 100644
--- a/gtk/gtktextview.c
+++ b/gtk/gtktextview.c
@@ -6417,7 +6417,7 @@ move_cursor (GtkTextView       *text_view,
 }
 
 static gboolean
-iter_line_is_rtl (GtkTextIter *iter)
+iter_line_is_rtl (const GtkTextIter *iter)
 {
   GtkTextIter start, end;
   char *text;