drm/i915/breadcrumbs: Reduce missed-breadcrumb false positive rate

Change the on-cpu check to on-runqueue to catch if the waiter has been
woken (and reset its current_state back to TASK_UNINTERRUPTIBLE to
perform the seqno check) but is sleeping due to being preempted off the
cpu.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181203113701.12106-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/intel_breadcrumbs.c

@@ -27,11 +27,7 @@
 
 #include "i915_drv.h"
 
-#ifdef CONFIG_SMP
-#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL && !(tsk)->on_cpu)
-#else
-#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL)
-#endif
+#define task_asleep(tsk) ((tsk)->state & TASK_NORMAL && !(tsk)->on_rq)
 
 static unsigned int __intel_breadcrumbs_wakeup(struct intel_breadcrumbs *b)
 {