Fix imgresample-test linking.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@9085 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/imgresample.c

@@ -815,6 +815,7 @@ the_end:
 
 #ifdef TEST
 #include <stdio.h>
+#undef exit
 
 /* input */
 #define XSIZE 256