[gtksourceview] StyleScheme: remove dead code (found by Coverity)

[Sébastien Wilmet <swilmet src gnome org>]

commit ee3a4a94d87e396ef9badfc7c0522497391384be
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Sun Jan 22 12:29:42 2017 +0100

    StyleScheme: remove dead code (found by Coverity)
    
    use_style is always NULL at this place.

 gtksourceview/gtksourcestylescheme.c |   10 ----------
 1 files changed, 0 insertions(+), 10 deletions(-)
---
diff --git a/gtksourceview/gtksourcestylescheme.c b/gtksourceview/gtksourcestylescheme.c
index a38573b..0f6d9e9 100644
--- a/gtksourceview/gtksourcestylescheme.c
+++ b/gtksourceview/gtksourcestylescheme.c
@@ -1040,16 +1040,6 @@ parse_style (GtkSourceStyleScheme *scheme,
        tmp = xmlGetProp (node, BAD_CAST "use-style");
        if (tmp != NULL)
        {
-               if (use_style != NULL)
-               {
-                       g_set_error (error, ERROR_QUARK, 0,
-                                    "in style '%s': duplicated use-style attribute",
-                                    style_name);
-                       g_free (style_name);
-                       g_object_unref (use_style);
-                       return FALSE;
-               }
-
                use_style = gtk_source_style_scheme_get_style (scheme, (char*) tmp);
 
                if (use_style == NULL)