drm/i915: Remove use of dev_priv->dev backpointer in __i915_printk()

As we can just directly use drm_dev->drm.dev, we do not need the
drm_dev->dev backpointer anymore and can also loose the warning about
order of __i915_printk() and our initialisation (which is now always
safe).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1467711623-2905-2-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Matthew Auld <matthew.auld@intel.com>

drivers/gpu/drm/i915/i915_drv.c

@@ -77,7 +77,7 @@ __i915_printk(struct drm_i915_private *dev_priv, const char *level,
 	      const char *fmt, ...)
 {
 	static bool shown_bug_once;
-	struct device *dev = dev_priv->dev->dev;
+	struct device *dev = dev_priv->drm.dev;
 	bool is_error = level[1] <= KERN_ERR[1];
 	bool is_debug = level[1] == KERN_DEBUG[1];
 	struct va_format vaf;
@@ -1234,7 +1234,6 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
 		return ret;
 	}
 
-	/* Must be set before calling __i915_printk */
 	dev_priv->drm.pdev = pdev;
 	dev_priv->drm.dev_private = dev_priv;
 	dev_priv->dev = &dev_priv->drm;