platform/mellanox: Remove unnecessary code

Remove redundant 'NULL' check for of if 'data->notifier'.

Replace 'return err' by 'return 0' in mlxreg_lc_probe().

Fixes: 62f9529b8d5c87b ("platform/mellanox: mlxreg-lc: Add initial support for Nvidia line card devices")
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Vadim Pasternak <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Hans de Goede <[e-mail]>
Signed-off-by: Hans de Goede <[e-mail]>

drivers/platform/mellanox/mlxreg-lc.c

···
 
 	mutex_init(&mlxreg_lc->lock);
 	/* Set event notification callback. */
-	if (data->notifier) {
-		data->notifier->user_handler = mlxreg_lc_event_handler;
-		data->notifier->handle = mlxreg_lc;
-	}
+	data->notifier->user_handler = mlxreg_lc_event_handler;
+	data->notifier->handle = mlxreg_lc;
+
 	data->hpdev.adapter = i2c_get_adapter(data->hpdev.nr);
 	if (!data->hpdev.adapter) {
 		dev_err(&pdev->dev, "Failed to get adapter for bus %d\n",
···
 	if (err)
 		goto mlxreg_lc_config_init_fail;
 
-	return err;
+	return 0;
 
 mlxreg_lc_config_init_fail:
 regcache_sync_fail: