drm/vmwgfx: Fix a couple of sparse warnings and errors

Introduced with 3.14-rc1

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
3 files changed