drm/i915: Convert dev_priv->dev backpointers to dev_priv->drm

Since drm_i915_private is now a subclass of drm_device we do not need to
chase the drm_i915_private->dev backpointer and can instead simply
access drm_i915_private->drm directly.

   text	   data	    bss	    dec	    hex	filename
1068757	   4565	    416	1073738	 10624a	drivers/gpu/drm/i915/i915.ko
1066949	   4565	    416	1071930	 105b3a	drivers/gpu/drm/i915/i915.ko

Created by the coccinelle script:
@@
struct drm_i915_private *d;
identifier i;
@@
(
- d->dev->i
+ d->drm.i
|
- d->dev
+ &d->drm
)

and for good measure the dev_priv->dev backpointer was removed entirely.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467711623-2905-4-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c
index 1bf1454..067632a 100644
--- a/drivers/gpu/drm/i915/i915_gem_shrinker.c
+++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c
@@ -257,7 +257,7 @@
 {
 	struct drm_i915_private *dev_priv =
 		container_of(shrinker, struct drm_i915_private, mm.shrinker);
-	struct drm_device *dev = dev_priv->dev;
+	struct drm_device *dev = &dev_priv->drm;
 	struct drm_i915_gem_object *obj;
 	unsigned long count;
 	bool unlock;
@@ -288,7 +288,7 @@
 {
 	struct drm_i915_private *dev_priv =
 		container_of(shrinker, struct drm_i915_private, mm.shrinker);
-	struct drm_device *dev = dev_priv->dev;
+	struct drm_device *dev = &dev_priv->drm;
 	unsigned long freed;
 	bool unlock;
 
@@ -323,7 +323,7 @@
 {
 	unsigned long timeout = msecs_to_jiffies(timeout_ms) + 1;
 
-	while (!i915_gem_shrinker_lock(dev_priv->dev, &slu->unlock)) {
+	while (!i915_gem_shrinker_lock(&dev_priv->drm, &slu->unlock)) {
 		schedule_timeout_killable(1);
 		if (fatal_signal_pending(current))
 			return false;
@@ -344,7 +344,7 @@
 {
 	dev_priv->mm.interruptible = slu->was_interruptible;
 	if (slu->unlock)
-		mutex_unlock(&dev_priv->dev->struct_mutex);
+		mutex_unlock(&dev_priv->drm.struct_mutex);
 }
 
 static int