I think, we may safely remove this exports, as:
- code_syscall is used only in one function, which now will have
  it as a parameter;
- code_syscall_size must be equall to BUILTIN_SYSCALL_SIZE under
  BUILD_BUG_ON, so BUILTIN_SYSCALL_SIZE may be used instead.
  (see ptrace(2) - align restriction to PTRACE_PEEKUSER).

This will reduce arch-depended code coupling a little.

(and I also interested in this because of I need __parasite_execute_syscall
to execute 32-bit syscall code on x86_64, which I prefer to leave without
some CONFIG_X86_64 as it's generic code)

Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>