x86/cpu: Fix __x86_return_thunk symbol type

stable inclusion
from stable-v5.10.192
commit d5b3c88d153cf10404dc9efb6b17ec2ff5e1dc67
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7RQ67

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=d5b3c88d153cf10404dc9efb6b17ec2ff5e1dc67



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commit 77f67119 upstream.

Commit

  fb3bd914 ("x86/srso: Add a Speculative RAS Overflow mitigation")

reimplemented __x86_return_thunk with a mix of SYM_FUNC_START and
SYM_CODE_END, this is not a sane combination.

Since nothing should ever actually 'CALL' this, make it consistently
CODE.

Fixes: fb3bd914 ("x86/srso: Add a Speculative RAS Overflow mitigation")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20230814121148.571027074@infradead.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>