drm/i915: Remove debug noise on detecting fault-injection of missed interrupts

Since the tests can and do explicitly check debugfs/i915_ring_missed_irqs
for the handling of a "missed interrupt", adding it to the dmesg at INFO
is just noise. When it happens for real, we still class it as an ERROR.

Note that I have chose to remove it entirely because when we detect the
"missed interrupt" is irrelevant and the message contains no more
information than we glean from looking in debugfs.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467390209-3576-20-git-send-email-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/i915_irq.c

@@ -3072,9 +3072,6 @@ static unsigned kick_waiters(struct intel_engine_cs *engine)
 		if (!test_bit(engine->id, &i915->gpu_error.test_irq_rings))
 			DRM_ERROR("Hangcheck timer elapsed... %s idle\n",
 				  engine->name);
-		else
-			DRM_INFO("Fake missed irq on %s\n",
-				 engine->name);
 
 		intel_engine_enable_fake_irq(engine);
 	}