x86/entry: Add __init to ia32_emulation_override_cmdline()

jira VULN-772
cve-pre CVE-2024-25744
commit-author Vitaly Kuznetsov <vkuznets@redhat.com>
commit d55f31e

ia32_emulation_override_cmdline() is an early_param() arg and these
are only needed at boot time. In fact, all other early_param() functions
in arch/x86 seem to have '__init' annotation and
ia32_emulation_override_cmdline() is the only exception.

Fixes: a11e097 ("x86: Make IA32_EMULATION boot time configurable")
	Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
	Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
	Signed-off-by: Ingo Molnar <mingo@kernel.org>
	Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/all/20241210151650.1746022-1-vkuznets%40redhat.com
(cherry picked from commit d55f31e)
	Signed-off-by: Marcin Wcisło <marcin.wcislo@conclusive.pl>

Author: pvts-mat

arch/x86/entry/common.c

@@ -100,7 +100,7 @@ static __always_inline int syscall_32_enter(struct pt_regs *regs)
 #ifdef CONFIG_IA32_EMULATION
 bool __ia32_enabled __ro_after_init = !IS_ENABLED(CONFIG_IA32_EMULATION_DEFAULT_DISABLED);
 
-static int ia32_emulation_override_cmdline(char *arg)
+static int __init ia32_emulation_override_cmdline(char *arg)
 {
 	return kstrtobool(arg, &__ia32_enabled);
 }