drm/i915: Drop the irqs_disabled() check

The !irqs_disabled() check triggers on PREEMPT_RT even with
i915_sched_engine::lock acquired. The reason is the lock is transformed
into a sleeping lock on PREEMPT_RT and does not disable interrupts.

There is no need to check for disabled interrupts. The lockdep
annotation below already check if the lock has been acquired by the
caller and will yell if the interrupts are not disabled.

Remove the !irqs_disabled() check.

Reported-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

drivers/gpu/drm/i915/i915_request.c

@@ -609,7 +609,6 @@ bool __i915_request_submit(struct i915_request *request)
 
 	RQ_TRACE(request, "\n");
 
-	GEM_BUG_ON(!irqs_disabled());
 	lockdep_assert_held(&engine->sched_engine->lock);
 
 	/*
@@ -718,7 +717,6 @@ void __i915_request_unsubmit(struct i915_request *request)
 	 */
 	RQ_TRACE(request, "\n");
 
-	GEM_BUG_ON(!irqs_disabled());
 	lockdep_assert_held(&engine->sched_engine->lock);
 
 	/*