score: remove init_mm

init_mm is now part of the common code and not provided
by the architecture any more.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/score/kernel/init_task.c

@@ -26,8 +26,6 @@
 
 static struct signal_struct init_signals = INIT_SIGNALS(init_signals);
 static struct sighand_struct init_sighand = INIT_SIGHAND(init_sighand);
-struct mm_struct init_mm = INIT_MM(init_mm);
-EXPORT_SYMBOL(init_mm);
 
 /*
  * Initial thread structure.