drm/i915: Tidy slab cache allocations

We can use the preferred KMEM_CACHE helper for brevity.

Also simplifiy error unwind by only setting the ENOMEM
error code once.

v2: Add forgotten changes. (Joonas Lahtinen)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> (v1)
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1478099699-28652-1-git-send-email-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/i915_gem.c

@@ -4714,39 +4714,22 @@ int
 i915_gem_load_init(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = to_i915(dev);
-	int err;
+	int err = -ENOMEM;
 
-	dev_priv->objects =
-		kmem_cache_create("i915_gem_object",
-				  sizeof(struct drm_i915_gem_object), 0,
-				  SLAB_HWCACHE_ALIGN,
-				  NULL);
-	if (!dev_priv->objects) {
-		err = -ENOMEM;
+	dev_priv->objects = KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
+	if (!dev_priv->objects)
 		goto err_out;
-	}
 
-	dev_priv->vmas =
-		kmem_cache_create("i915_gem_vma",
-				  sizeof(struct i915_vma), 0,
-				  SLAB_HWCACHE_ALIGN,
-				  NULL);
-	if (!dev_priv->vmas) {
-		err = -ENOMEM;
+	dev_priv->vmas = KMEM_CACHE(i915_vma, SLAB_HWCACHE_ALIGN);
+	if (!dev_priv->vmas)
 		goto err_objects;
-	}
 
-	dev_priv->requests =
-		kmem_cache_create("i915_gem_request",
-				  sizeof(struct drm_i915_gem_request), 0,
-				  SLAB_HWCACHE_ALIGN |
-				  SLAB_RECLAIM_ACCOUNT |
-				  SLAB_DESTROY_BY_RCU,
-				  NULL);
-	if (!dev_priv->requests) {
-		err = -ENOMEM;
+	dev_priv->requests = KMEM_CACHE(drm_i915_gem_request,
+					SLAB_HWCACHE_ALIGN |
+					SLAB_RECLAIM_ACCOUNT |
+					SLAB_DESTROY_BY_RCU);
+	if (!dev_priv->requests)
 		goto err_vmas;
-	}
 
 	mutex_lock(&dev_priv->drm.struct_mutex);
 	INIT_LIST_HEAD(&dev_priv->gt.timelines);