Remove unused function parameter from cpu_restore_state

The previous patch removed the need for parameter puc.
Is is now unused, so remove it.

Cc: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefan Weil <weil@mail.berlios.de>
diff --git a/target-m68k/op_helper.c b/target-m68k/op_helper.c
index 0711107..9b13bdb 100644
--- a/target-m68k/op_helper.c
+++ b/target-m68k/op_helper.c
@@ -68,7 +68,7 @@
             if (tb) {
                 /* the PC is inside the translated code. It means that we have
                    a virtual CPU fault */
-                cpu_restore_state(tb, env, pc, NULL);
+                cpu_restore_state(tb, env, pc);
             }
         }
         cpu_loop_exit();