drm/qxl: Replace module-init boiler-plate code with DRM helpers

Remove custom qxl_init() and qxl_exit() functions and initialize
the module with DRM module helpers.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211217144615.32733-9-tzimmermann@suse.de

drivers/gpu/drm/qxl/qxl_drv.c

@@ -39,6 +39,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_gem_ttm_helper.h>
+#include <drm/drm_module.h>
 #include <drm/drm_modeset_helper.h>
 #include <drm/drm_prime.h>
 #include <drm/drm_probe_helper.h>
@@ -303,23 +304,7 @@ static struct drm_driver qxl_driver = {
 	.release = qxl_drm_release,
 };
 
-static int __init qxl_init(void)
-{
-	if (drm_firmware_drivers_only() && qxl_modeset == -1)
-		return -EINVAL;
-
-	if (qxl_modeset == 0)
-		return -EINVAL;
-	return pci_register_driver(&qxl_pci_driver);
-}
-
-static void __exit qxl_exit(void)
-{
-	pci_unregister_driver(&qxl_pci_driver);
-}
-
-module_init(qxl_init);
-module_exit(qxl_exit);
+drm_module_pci_driver_if_modeset(qxl_pci_driver, qxl_modeset);
 
 MODULE_AUTHOR(DRIVER_AUTHOR);
 MODULE_DESCRIPTION(DRIVER_DESC);