x86/asm/32: Fix ANNOTATE_UNRET_SAFE use on 32-bit

stable inclusion
from stable-v5.10.133
commit ecc0d92a9f6cc3f74b67d2c9887d0c800018e661
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YVKO

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ecc0d92a9f6cc3f74b67d2c9887d0c800018e661



--------------------------------

commit 3131ef39 upstream.

The build on x86_32 currently fails after commit

  9bb2ec60 (objtool: Update Retpoline validation)

with:

  arch/x86/kernel/../../x86/xen/xen-head.S:35: Error: no such instruction: `annotate_unret_safe'

ANNOTATE_UNRET_SAFE is defined in nospec-branch.h. And head_32.S is
missing this include. Fix this.

Fixes: 9bb2ec60 ("objtool: Update Retpoline validation")
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/63e23f80-033f-f64e-7522-2816debbc367@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>