staging: gasket: fix class create bug handling

class_create() never returns NULL, and this driver should never return
PTR_ERR(NULL) anyway.
Reported-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Zhongze Hu <frankhu@chromium.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/gasket/gasket_core.c

@@ -321,7 +321,7 @@ int gasket_register_device(const struct gasket_driver_desc *driver_desc)
 	internal->class =
 		class_create(driver_desc->module, driver_desc->name);
 
-	if (IS_ERR_OR_NULL(internal->class)) {
+	if (IS_ERR(internal->class)) {
 		gasket_nodev_error("Cannot register %s class [ret=%ld]",
 				   driver_desc->name, PTR_ERR(internal->class));
 		ret = PTR_ERR(internal->class);