x86/ACPI: Move scheduler enable/disable calls out of {freeze,thaw}_domains()

... and into their parent, enter_state().  This change addresses the concern
about misleading function semantics, as the scheduler operations are not
directly related to the domain pausing/resuming implied by the freeze/thaw
naming.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Mykola Kvach <mykola_kvach@epam.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/arch/x86/acpi/power.c

@@ -151,16 +151,12 @@ static void freeze_domains(void)
     for_each_domain ( d )
         domain_pause(d);
     rcu_read_unlock(&domlist_read_lock);
-
-    scheduler_disable();
 }
 
 static void thaw_domains(void)
 {
     struct domain *d;
 
-    scheduler_enable();
-
     rcu_read_lock(&domlist_read_lock);
     for_each_domain ( d )
         domain_unpause(d);
@@ -216,6 +212,7 @@ static int enter_state(u32 state)
     printk(XENLOG_INFO "Preparing system for ACPI S%d state.\n", state);
 
     freeze_domains();
+    scheduler_disable();
 
     acpi_dmar_reinstate();
 
@@ -334,6 +331,7 @@ static int enter_state(u32 state)
     mtrr_aps_sync_end();
     iommu_adjust_irq_affinities();
     acpi_dmar_zap();
+    scheduler_enable();
     thaw_domains();
     system_state = SYS_STATE_active;
     spin_unlock(&pm_lock);