configure.ac: remove unnecessary AC_SUBST's added by commit 38ef6789909c
diff --git a/test/configure.ac b/test/configure.ac
index 3d37b6a..694551c 100644
--- a/test/configure.ac
+++ b/test/configure.ac
@@ -99,15 +99,6 @@ AC_SUBST(ISWINDOWS)
AC_SUBST(ISUNIX)
AC_SUBST(ISOS2)
-AC_SUBST([prefix])
-AC_SUBST([exec_prefix])
-AC_SUBST([bindir])
-AC_SUBST([libdir])
-AC_SUBST([libexecdir])
-AC_SUBST([includedir])
-AC_SUBST([datarootdir])
-AC_SUBST([datadir])
-
dnl Check for SDL
SDL_VERSION=2.0.18
AM_PATH_SDL2($SDL_VERSION,