spi: Kill spi_add_device_locked()

Now, spi_add_device_locked() has just a line on top of __spi_add_device().
Besides that, it has a single caller. So, just kill it and embed its parts
into the caller.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230714091748.89681-3-andriy.shevchenko@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -708,14 +708,6 @@ int spi_add_device(struct spi_device *spi)
 }
 EXPORT_SYMBOL_GPL(spi_add_device);
 
-static int spi_add_device_locked(struct spi_device *spi)
-{
-	struct spi_controller *ctlr = spi->controller;
-
-	WARN_ON(!mutex_is_locked(&ctlr->add_lock));
-	return __spi_add_device(spi);
-}
-
 /**
  * spi_new_device - instantiate one new SPI device
  * @ctlr: Controller to which device is connected
@@ -2417,11 +2409,12 @@ static void of_register_spi_devices(struct spi_controller *ctlr) { }
 struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
 					     u8 chip_select)
 {
+	struct spi_controller *ctlr = spi->controller;
 	struct spi_device *ancillary;
 	int rc = 0;
 
 	/* Alloc an spi_device */
-	ancillary = spi_alloc_device(spi->controller);
+	ancillary = spi_alloc_device(ctlr);
 	if (!ancillary) {
 		rc = -ENOMEM;
 		goto err_out;
@@ -2436,8 +2429,10 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
 	ancillary->max_speed_hz = spi->max_speed_hz;
 	ancillary->mode = spi->mode;
 
+	WARN_ON(!mutex_is_locked(&ctlr->add_lock));
+
 	/* Register the new device */
-	rc = spi_add_device_locked(ancillary);
+	rc = __spi_add_device(ancillary);
 	if (rc) {
 		dev_err(&spi->dev, "failed to register ancillary device\n");
 		goto err_out;