leds: pca955x: Add ACPI support

Hello Tin Huynh,

This is a semi-automatic email about new static checker warnings.

The patch f00662b45979: "leds: pca955x: Add ACPI support" from Nov 30, 2016, leads to the following Smatch complaint:

drivers/leds/leds-pca955x.c:284 pca955x_probe()
error: we previously assumed 'id' could be null (see line 263)

drivers/leds/leds-pca955x.c
262

   263		if (id) {
                   ^^^^

We added a new NULL check.

264 chip = &pca955x_chipdefs[id->driver_data];
265 } else {
266 const struct acpi_device_id *acpi_id;
267
268 acpi_id = acpi_match_device(pca955x_acpi_ids, &client->dev);
269 if (!acpi_id)
270 return -ENODEV;
271 chip = &pca955x_chipdefs[acpi_id->driver_data];
272 }
273 adapter = to_i2c_adapter(client->dev.parent);
274 pdata = dev_get_platdata(&client->dev);
275
276 /* Make sure the slave address / chip type combo given is possible */
277 if ((client->addr & ~((1 << chip->slv_addr_shift) - 1)) !=
278 chip->slv_addr) {
279 dev_err(&client->dev, "invalid slave address %02x\n",
280 client->addr);
281 return -ENODEV;
282 }
283
284 dev_info(&client->dev, "leds-pca955x: Using %s %d-bit LED driver at "
285 "slave address 0x%02x\n",

   286				id->name, chip->bits, client->addr);
                                ^^^^^^^^^

But the old code assumed "id" was non-NULL.

regards,
dan carpenter