i2c: replace i2c_new_secondary_device with an ERR_PTR variant

In the general move to have i2c_new_*_device functions which return
ERR_PTR instead of NULL, this patch converts i2c_new_secondary_device().

There are only few users, so this patch converts the I2C core and all
users in one go. The function gets renamed to i2c_new_ancillary_device()
so out-of-tree users will get a build failure to understand they need to
adapt their error checking code.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> # adv748x
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> # adv7511 + adv7604
Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> # adv7604
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index b4d84bd..ca10525 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -964,7 +964,7 @@ struct i2c_client *devm_i2c_new_dummy_device(struct device *dev,
 EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
 
 /**
- * i2c_new_secondary_device - Helper to get the instantiated secondary address
+ * i2c_new_ancillary_device - Helper to get the instantiated secondary address
  * and create the associated device
  * @client: Handle to the primary client
  * @name: Handle to specify which secondary address to get
@@ -983,9 +983,9 @@ EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device);
  * cell whose "reg-names" value matches the slave name.
  *
  * This returns the new i2c client, which should be saved for later use with
- * i2c_unregister_device(); or NULL to indicate an error.
+ * i2c_unregister_device(); or an ERR_PTR to describe the error.
  */
-struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
+struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client,
 						const char *name,
 						u16 default_addr)
 {
@@ -1000,9 +1000,9 @@ struct i2c_client *i2c_new_secondary_device(struct i2c_client *client,
 	}
 
 	dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr);
-	return i2c_new_dummy(client->adapter, addr);
+	return i2c_new_dummy_device(client->adapter, addr);
 }
-EXPORT_SYMBOL_GPL(i2c_new_secondary_device);
+EXPORT_SYMBOL_GPL(i2c_new_ancillary_device);
 
 /* ------------------------------------------------------------------------- */