drm/vkms: Use new return type vm_fault_t

Use new return type vm_fault_t for fault handler.

Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180726144549.GA9434@jordon-HP-15-Notebook-PC

drivers/gpu/drm/vkms/vkms_drv.h

@@ -81,7 +81,7 @@ struct drm_gem_object *vkms_gem_create(struct drm_device *dev,
 				       u32 *handle,
 				       u64 size);
 
-int vkms_gem_fault(struct vm_fault *vmf);
+vm_fault_t vkms_gem_fault(struct vm_fault *vmf);
 
 int vkms_dumb_create(struct drm_file *file, struct drm_device *dev,
 		     struct drm_mode_create_dumb *args);