labs: interrupts: Fix release of DATA_REG

In the touched code we are trying to request two regions. But in the
case when the first request would succeed and the second one fail, we
would not correctly free the first region on the error path.

This commit fixes that by introducing an additional label and changing
a goto destination.

Author: vlasakm

tools/labs/templates/interrupts/kbd.c

@@ -223,7 +223,7 @@ static int kbd_init(void)
 	}
 	if (request_region(I8042_STATUS_REG+1, 1, MODULE_NAME) == NULL) {
 		err = -EBUSY;
-		goto out_unregister;
+		goto out_release_region;
 	}
 
 	/* TODO 3: initialize spinlock */
@@ -244,9 +244,10 @@ static int kbd_init(void)
 	pr_notice("Driver %s loaded\n", MODULE_NAME);
 	return 0;
 
-	/*TODO 2/3: release regions in case of error */
+	/*TODO 2/4: release regions in case of error */
 out_release_regions:
 	release_region(I8042_STATUS_REG+1, 1);
+out_release_region:
 	release_region(I8042_DATA_REG+1, 1);
 
 out_unregister: