x86/speculation: Move arch_smt_update() call to after mitigation decisions

arch_smt_update() now has a dependency on both Spectre v2 and MDS
mitigations.  Move its initial call to after all the mitigation decisions
have been made.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>

arch/x86/kernel/cpu/bugs.c

@@ -111,6 +111,8 @@ void __init check_bugs(void)
 
 	mds_select_mitigation();
 
+	arch_smt_update();
+
 #ifdef CONFIG_X86_32
 	/*
 	 * Check whether we are able to run this kernel safely on SMP.
@@ -638,9 +640,6 @@ static void __init spectre_v2_select_mitigation(void)
 
 	/* Set up IBPB and STIBP depending on the general spectre V2 command */
 	spectre_v2_user_select_mitigation(cmd);
-
-	/* Enable STIBP if appropriate */
-	arch_smt_update();
 }
 
 static void update_stibp_msr(void * __unused)