x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE

x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE

As userspace knows nothing about kernel config, thus #ifdefs
around ABI prctl constants makes them invisible to userspace.

Let it be clean'n'simple: remove #ifdefs.

If kernel has CONFIG_CHECKPOINT_RESTORE disabled, sys_prctl()
will return -EINVAL for those prctls.

Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: oleg@redhat.com
Fixes: 2eefd8789698 ("x86/arch_prctl/vdso: Add ARCH_MAP_VDSO_*")
Link: http://lkml.kernel.org/r/20161027141516.28447-2-dsafonov@virtuozzo.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>