[dia] xslt: fix xsltSaveResultToFile() return value handling

[Hans Breuer <hans src gnome org>]

commit 331f5d8dcba6fa8f4260898eaa076e65cfde553f
Author: Hans Breuer <hans breuer org>
Date:   Sun Jan 8 12:49:31 2012 +0100

    xslt: fix xsltSaveResultToFile() return value handling

 plug-ins/xslt/xslt.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/plug-ins/xslt/xslt.c b/plug-ins/xslt/xslt.c
index 6b86a24..01caad4 100644
--- a/plug-ins/xslt/xslt.c
+++ b/plug-ins/xslt/xslt.c
@@ -146,9 +146,9 @@ xslt_ok(void)
 		return;
 	}
 
-
+	/* Returns the number of byte written or -1 in case of failure. */
 	err = xsltSaveResultToFile(out, doc, codestyle);
-	if(err != 0) {
+	if(err < 0) {
 		message_error(_("Error while saving result: %s\n"), 
 			      dia_message_filename(filename));
 		return;