drm/i915: Fix __user sparse warning

CHECK   linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47: warning: incorrect type in initializer (different address spaces)
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47:    expected struct drm_i915_gem_exec_object2 *user_exec_list
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1529:47:    got void [noderef] <asn:1>*
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61: warning: incorrect type in argument 1 (different address spaces)
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61:    expected void [noderef] <asn:1>*dst
linux/drivers/gpu/drm/i915/i915_gem_execbuffer.c:1533:61:    got unsigned long long *<noident>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_gem_execbuffer.c

@@ -1525,7 +1525,7 @@ i915_gem_execbuffer2(struct drm_device *dev, void *data,
 	ret = i915_gem_do_execbuffer(dev, data, file, args, exec2_list);
 	if (!ret) {
 		/* Copy the new buffer offsets back to the user's exec list. */
-		struct drm_i915_gem_exec_object2 *user_exec_list =
+		struct drm_i915_gem_exec_object2 __user *user_exec_list =
 				   to_user_ptr(args->buffers_ptr);
 		int i;