firewire: core: use cleanup function to release cached configuration ROM

When returning from read_config_rom() function, the allocated buffer and
the previous buffer for configuration ROM should be released. The cleanup
function is useful in the case.

This commit uses the cleanup function to remove goto statements.

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Takashi Sakamoto <[e-mail]>

drivers/firewire/core-device.c

···
 static int read_config_rom(struct fw_device *device, int generation)
 {
 	struct fw_card *card = device->card;
-	const u32 *old_rom, *new_rom;
-	u32 *rom, *stack;
+	const u32 *new_rom, *old_rom __free(kfree) = NULL;
+	u32 *stack, *rom __free(kfree) = NULL;
 	u32 sp, key;
 	int i, end, length, ret, speed;
 	int quirks;
···
 	for (i = 0; i < 5; i++) {
 		ret = read_rom(device, generation, speed, i, &rom[i]);
 		if (ret != RCODE_COMPLETE)
-			goto out;
+			return ret;
 		/*
 		 * As per IEEE1212 7.2, during initialization, devices can
 		 * reply with a 0 for the first quadlet of the config
···
 		 * harddisk).  In that case we just fail, and the
 		 * retry mechanism will try again later.
 		 */
-		if (i == 0 && rom[i] == 0) {
-			ret = RCODE_BUSY;
-			goto out;
-		}
+		if (i == 0 && rom[i] == 0)
+			return RCODE_BUSY;
 	}
 
 	quirks = detect_quirks_by_bus_information_block(rom);
···
 		 */
 		key = stack[--sp];
 		i = key & 0xffffff;
-		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) {
-			ret = -ENXIO;
-			goto out;
-		}
+		if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE))
+			return -ENXIO;
 
 		/* Read header quadlet for the block to get the length. */
 		ret = read_rom(device, generation, speed, i, &rom[i]);
 		if (ret != RCODE_COMPLETE)
-			goto out;
+			return ret;
 		end = i + (rom[i] >> 16) + 1;
 		if (end > MAX_CONFIG_ROM_SIZE) {
 			/*
···
 		for (; i < end; i++) {
 			ret = read_rom(device, generation, speed, i, &rom[i]);
 			if (ret != RCODE_COMPLETE)
-				goto out;
+				return ret;
 
 			if ((key >> 30) != 3 || (rom[i] >> 30) < 2)
 				continue;
···
 
 	old_rom = device->config_rom;
 	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);
-	if (new_rom == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (new_rom == NULL)
+		return -ENOMEM;
 
 	scoped_guard(rwsem_write, &fw_device_rwsem) {
 		device->config_rom = new_rom;
 		device->config_rom_length = length;
 	}
 
-	kfree(old_rom);
-	ret = RCODE_COMPLETE;
 	device->max_rec	= rom[2] >> 12 & 0xf;
 	device->cmc	= rom[2] >> 30 & 1;
 	device->irmc	= rom[2] >> 31 & 1;
- out:
-	kfree(rom);
 
-	return ret;
+	return RCODE_COMPLETE;
 }
 
 static void fw_unit_release(struct device *dev)