[rhythmbox] header: use the right abs() function

[Jonathan Matthew <jmatthew src gnome org>]

commit d899e50a91b472f149886ec315ea1192d9720fdb
Author: Jonathan Matthew <jonathan d14n org>
Date:   Wed Nov 3 22:18:44 2021 +1000

    header: use the right abs() function
    
    clang 11 complained about this

 widgets/rb-header.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/widgets/rb-header.c b/widgets/rb-header.c
index 76b214aee..6ea9d65db 100644
--- a/widgets/rb-header.c
+++ b/widgets/rb-header.c
@@ -1042,7 +1042,7 @@ slider_press_callback (GtkWidget *widget,
 
        /* hack: pretend the trough is at least 20 pixels high */
        height = gtk_widget_get_allocated_height (widget);
-       if (abs (event->y - (height / 2)) < 10)
+       if (fabs (event->y - (height / 2)) < 10)
                event->y = height / 2;
 
        return FALSE;