multimedia/vdr: unbreak with clang 4.0

recording.c:2090:17: error: ordered comparison between pointer and zero ('cUnbufferedFile *' and 'int')
     if (Open() >= 0) {
         ~~~~~~ ^  ~

PR:		216058
Reported by:	antoine (via exp-run)

multimedia/vdr/Makefile

@@ -3,7 +3,7 @@
 
 PORTNAME=	vdr
 PORTVERSION=	1.7.29
-PORTREVISION=	7
+PORTREVISION=	8
 CATEGORIES=	multimedia
 MASTER_SITES=	ftp://ftp.tvdr.de/vdr/Developer/
 DIST_SUBDIR=	vdr

multimedia/vdr/files/patch-clang40

@@ -0,0 +1,11 @@
+--- recording.c.orig	2012-06-09 13:57:30 UTC
++++ recording.c
+@@ -2075,7 +2075,7 @@ cUnbufferedFile *cFileName::SetOffset(in
+            }
+         // found a non existing file suffix
+         }
+-     if (Open() >= 0) {
++     if (Open()) {
+         if (!record && Offset >= 0 && file && file->Seek(Offset, SEEK_SET) != Offset) {
+            LOG_ERROR_STR(fileName);
+            return NULL;