drm/i915: Remove redundant initialisation of per-ring IRQ waitqueues

The waitqueues are already initialised during ring initialisation so
kill the redundant and duplicated code to do so in each generations IRQ
installer.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_irq.c

@@ -2085,12 +2085,6 @@ static int ironlake_irq_postinstall(struct drm_device *dev)
 	u32 render_irqs;
 	u32 hotplug_mask;
 
-	DRM_INIT_WAITQUEUE(&dev_priv->ring[RCS].irq_queue);
-	if (HAS_BSD(dev))
-		DRM_INIT_WAITQUEUE(&dev_priv->ring[VCS].irq_queue);
-	if (HAS_BLT(dev))
-		DRM_INIT_WAITQUEUE(&dev_priv->ring[BCS].irq_queue);
-
 	dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 	dev_priv->irq_mask = ~display_mask;
 
@@ -2160,12 +2154,6 @@ static int ivybridge_irq_postinstall(struct drm_device *dev)
 	u32 render_irqs;
 	u32 hotplug_mask;
 
-	DRM_INIT_WAITQUEUE(&dev_priv->ring[RCS].irq_queue);
-	if (HAS_BSD(dev))
-		DRM_INIT_WAITQUEUE(&dev_priv->ring[VCS].irq_queue);
-	if (HAS_BLT(dev))
-		DRM_INIT_WAITQUEUE(&dev_priv->ring[BCS].irq_queue);
-
 	dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;
 	dev_priv->irq_mask = ~display_mask;
 
@@ -2216,11 +2204,6 @@ static int valleyview_irq_postinstall(struct drm_device *dev)
 
 	dev_priv->irq_mask = ~enable_mask;
 
-
-	DRM_INIT_WAITQUEUE(&dev_priv->ring[RCS].irq_queue);
-	DRM_INIT_WAITQUEUE(&dev_priv->ring[VCS].irq_queue);
-	DRM_INIT_WAITQUEUE(&dev_priv->ring[BCS].irq_queue);
-
 	dev_priv->pipestat[0] = 0;
 	dev_priv->pipestat[1] = 0;