Fix iseeking_example #includes.

Unless you're using the autotools build system, <vorbis/...> doesn't exist, and
 could pull out-of-date system headers anyway.
ivorbisfile_example had the same problem, but that fix was accidentally
 included in r17526.


git-svn-id: https://svn.xiph.org/trunk/Tremor@17532 0101bb08-14d6-0310-b084-bc0e0c8e3800

iseeking_example.c

@@ -18,8 +18,8 @@
 
 #include <stdlib.h>
 #include <stdio.h>
-#include <vorbis/ivorbiscodec.h>
-#include <vorbis/ivorbisfile.h>
+#include "ivorbiscodec.h"
+#include "ivorbisfile.h"
 
 #ifdef _WIN32 /* We need the following two to set stdin/stdout to binary */
 # include <io.h>