drm/i915: No need to save/restore irq status in intel_engine_wakeup

It is called from either the process or timer context so it is
correct to always disable interrupts.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/20170306150321.29024-1-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/intel_breadcrumbs.c

@@ -46,12 +46,11 @@ static unsigned int __intel_breadcrumbs_wakeup(struct intel_breadcrumbs *b)
 unsigned int intel_engine_wakeup(struct intel_engine_cs *engine)
 {
 	struct intel_breadcrumbs *b = &engine->breadcrumbs;
-	unsigned long flags;
 	unsigned int result;
 
-	spin_lock_irqsave(&b->irq_lock, flags);
+	spin_lock_irq(&b->irq_lock);
 	result = __intel_breadcrumbs_wakeup(b);
-	spin_unlock_irqrestore(&b->irq_lock, flags);
+	spin_unlock_irq(&b->irq_lock);
 
 	return result;
 }