drm/i915: Mass convert dev->dev_private to to_i915(dev)

Since we now subclass struct drm_device, we can save pointer dances by
noting the equivalence of struct drm_device and struct drm_i915_private,
i.e. by using to_i915().

   text    data     bss     dec     hex filename
1073824    4562     416 1078802  107612 drivers/gpu/drm/i915/i915.ko
1068976    4562     416 1073954  106322 drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:

@@
expression E;
identifier p;
@@
- struct drm_i915_private *p = E->dev_private;
+ struct drm_i915_private *p = to_i915(E);

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Dave Gordon <david.s.gordon@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467628477-25379-1-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 3fafc35..428ed62 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2837,7 +2837,7 @@
 
 int intel_init_render_ring_buffer(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[RCS];
 	int ret;
 
@@ -2899,7 +2899,7 @@
 
 int intel_init_bsd_ring_buffer(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[VCS];
 
 	engine->name = "bsd ring";
@@ -2937,7 +2937,7 @@
  */
 int intel_init_bsd2_ring_buffer(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[VCS2];
 
 	engine->name = "bsd2 ring";
@@ -2957,7 +2957,7 @@
 
 int intel_init_blt_ring_buffer(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[BCS];
 
 	engine->name = "blitter ring";
@@ -2980,7 +2980,7 @@
 
 int intel_init_vebox_ring_buffer(struct drm_device *dev)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_engine_cs *engine = &dev_priv->engine[VECS];
 
 	engine->name = "video enhancement ring";