nvmem: core: fix leaks on registration errors

Make sure to deregister and release the nvmem device and underlying
memory on registration errors.

Note that the private data must be freed using put_device() once the
struct device has been initialised.

Also note that there's a related reference leak in the deregistration
function as reported by Mika Westerberg which is being fixed separately.

Fixes: b6c217ab9b ("nvmem: Add backwards compatibility support for older EEPROM drivers.")
Fixes: eace75cfdc ("nvmem: Add a simple NVMEM framework for nvmem providers")
Cc: stable <stable@vger.kernel.org>     # 4.3
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/core.c

@@ -489,21 +489,24 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config)
 
 	rval = device_add(&nvmem->dev);
 	if (rval)
-		goto out;
+		goto err_put_device;
 
 	if (config->compat) {
 		rval = nvmem_setup_compat(nvmem, config);
 		if (rval)
-			goto out;
+			goto err_device_del;
 	}
 
 	if (config->cells)
 		nvmem_add_cells(nvmem, config);
 
 	return nvmem;
-out:
-	ida_simple_remove(&nvmem_ida, nvmem->id);
-	kfree(nvmem);
+
+err_device_del:
+	device_del(&nvmem->dev);
+err_put_device:
+	put_device(&nvmem->dev);
+
 	return ERR_PTR(rval);
 }
 EXPORT_SYMBOL_GPL(nvmem_register);