x86: Fix objtool build warning

Offering: HULK
hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5PTAS
CVE: CVE-2022-29900,CVE-2022-23816,CVE-2022-29901

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fix these build warning
arch/x86/lib/copy_page_64.o: warning: objtool: copy_page_nocache()+0xdf: 'naked' return found in RETHUNK build
arch/x86/lib/copy_page_64.o: warning: objtool: copy_page_nocache_barrir()+0x3: 'naked' return found in RETHUNK build

The reference 5.10-stable branch  patches are as follows:
3c91e2257622 x86: Prepare asm files for straight-line-speculation
Signed-off-by: NLin Yujun <linyujun809@huawei.com>
Reviewed-by: NZhang Jianhua <chris.zjh@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

arch/x86/lib/copy_page_64.S

@@ -153,10 +153,10 @@ SYM_FUNC_START(copy_page_nocache)
 	movq	(%rsp), %rbx
 	movq	1*8(%rsp), %r12
 	addq	$2*8, %rsp
-	ret
+	RET
 SYM_FUNC_END(copy_page_nocache)
 
 SYM_FUNC_START(copy_page_nocache_barrir)
 	ALTERNATIVE "", "sfence", X86_FEATURE_XMM2
-	ret
+	RET
 SYM_FUNC_END(copy_page_nocache_barrir)