x86/bugs: Use switch/case in its_apply_mitigation()
Prepare to apply stuffing mitigation in its_apply_mitigation(). This is
currently only done via retbleed mitigation. Also using switch/case
makes it evident that mitigation mode like VMEXIT_ONLY doesn't need any
special handling.
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Nikolay Borisov <nik.borisov@suse.com>
Link: https://lore.kernel.org/20250611-eibrs-fix-v4-4-5ff86cac6c61@linux.intel.com