firmware: google: make coreboot driver's remove callback return void

All coreboot drivers return 0 unconditionally in their remove callback.
Also the device core ignores the return value of the struct
bus_type::remove(), so make the coreboot remove callback return void
instead of giving driver authors the illusion they could return an error
code here.

All drivers are adapted accordingly.
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Link: https://lore.kernel.org/r/20210126215339.706021-1-uwe@kleine-koenig.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/firmware/google/coreboot_table.c

@@ -46,14 +46,13 @@ static int coreboot_bus_probe(struct device *dev)
 
 static int coreboot_bus_remove(struct device *dev)
 {
-	int ret = 0;
 	struct coreboot_device *device = CB_DEV(dev);
 	struct coreboot_driver *driver = CB_DRV(dev->driver);
 
 	if (driver->remove)
-		ret = driver->remove(device);
+		driver->remove(device);
 
-	return ret;
+	return 0;
 }
 
 static struct bus_type coreboot_bus_type = {

drivers/firmware/google/coreboot_table.h

@@ -72,7 +72,7 @@ struct coreboot_device {
 /* A driver for handling devices described in coreboot tables. */
 struct coreboot_driver {
 	int (*probe)(struct coreboot_device *);
-	int (*remove)(struct coreboot_device *);
+	void (*remove)(struct coreboot_device *);
 	struct device_driver drv;
 	u32 tag;
 };

drivers/firmware/google/framebuffer-coreboot.c

@@ -72,13 +72,11 @@ static int framebuffer_probe(struct coreboot_device *dev)
 	return PTR_ERR_OR_ZERO(pdev);
 }
 
-static int framebuffer_remove(struct coreboot_device *dev)
+static void framebuffer_remove(struct coreboot_device *dev)
 {
 	struct platform_device *pdev = dev_get_drvdata(&dev->dev);
 
 	platform_device_unregister(pdev);
-
-	return 0;
 }
 
 static struct coreboot_driver framebuffer_driver = {

drivers/firmware/google/memconsole-coreboot.c

@@ -91,11 +91,9 @@ static int memconsole_probe(struct coreboot_device *dev)
 	return memconsole_sysfs_init();
 }
 
-static int memconsole_remove(struct coreboot_device *dev)
+static void memconsole_remove(struct coreboot_device *dev)
 {
 	memconsole_exit();
-
-	return 0;
 }
 
 static struct coreboot_driver memconsole_driver = {

drivers/firmware/google/vpd.c

@@ -298,14 +298,12 @@ static int vpd_probe(struct coreboot_device *dev)
 	return 0;
 }
 
-static int vpd_remove(struct coreboot_device *dev)
+static void vpd_remove(struct coreboot_device *dev)
 {
 	vpd_section_destroy(&ro_vpd);
 	vpd_section_destroy(&rw_vpd);
 
 	kobject_put(vpd_kobj);
-
-	return 0;
 }
 
 static struct coreboot_driver vpd_driver = {