Error out if we have no default path

The path is set through configure.ac/Makefile.am and always defined anyway.
Let's not re-define it here with a different value than our default.
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

xkbpath.c

@@ -33,10 +33,6 @@
 #include <X11/extensions/XKM.h>
 #include "xkbpath.h"
 
-#ifndef DFLT_XKB_CONFIG_ROOT
-#define DFLT_XKB_CONFIG_ROOT	"/usr/lib/X11/xkb"
-#endif
-
 #ifndef PATH_MAX
 #define	PATH_MAX 1024
 #endif