scsi: fcoe: Make fcoe_bus_type const

Now that the driver core can properly handle constant struct bus_type, move
the fcoe_bus_type variable to be a constant structure as well, placing it
into read-only memory which can not be modified at runtime.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Link: https://lore.kernel.org/r/20240203-bus_cleanup-scsi-v1-1-6f552fb24f71@marliere.netReviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/fcoe/fcoe_sysfs.c

@@ -597,7 +597,7 @@ static const struct attribute_group *fcoe_fcf_attr_groups[] = {
 	NULL,
 };
 
-static struct bus_type fcoe_bus_type;
+static const struct bus_type fcoe_bus_type;
 
 static int fcoe_bus_match(struct device *dev,
 			  struct device_driver *drv)
@@ -664,7 +664,7 @@ static struct attribute *fcoe_bus_attrs[] = {
 };
 ATTRIBUTE_GROUPS(fcoe_bus);
 
-static struct bus_type fcoe_bus_type = {
+static const struct bus_type fcoe_bus_type = {
 	.name = "fcoe",
 	.match = &fcoe_bus_match,
 	.bus_groups = fcoe_bus_groups,