[dia] [cleanup] remove superfluous prototype and comment

[Hans Breuer <hans src gnome org>]

commit f06f74af6efde36150554b575a9d1c2984542a63
Author: Hans Breuer <hans breuer org>
Date:   Wed Oct 1 20:09:07 2014 +0200

    [cleanup] remove superfluous prototype and comment

 objects/custom_lines/line_info.c |    5 +----
 1 files changed, 1 insertions(+), 4 deletions(-)
---
diff --git a/objects/custom_lines/line_info.c b/objects/custom_lines/line_info.c
index ddedd63..c3b6e86 100644
--- a/objects/custom_lines/line_info.c
+++ b/objects/custom_lines/line_info.c
@@ -46,10 +46,7 @@ char* custom_linetype_strings[] = {
 };
 
 
-/* to go in customline_util.c/h */
-gchar *
-custom_get_relative_filename(const gchar *current, const gchar *relative);
-gchar *
+static gchar *
 custom_get_relative_filename(const gchar *current, const gchar *relative)
 {
   gchar *dirname, *tmp;