scsi: iscsi: Fix reference count leak in iscsi_boot_create_kobj

kobject_init_and_add() takes reference even when it fails. If this
function returns an error, kobject_put() must be called to properly
clean up the memory associated with the object.

Link: https://lore.kernel.org/r/[e-mail]
Reviewed-by: Lee Duncan <[e-mail]>
Signed-off-by: Qiushi Wu <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/iscsi_boot_sysfs.c

···
 	boot_kobj->kobj.kset = boot_kset->kset;
 	if (kobject_init_and_add(&boot_kobj->kobj, &iscsi_boot_ktype,
 				 NULL, name, index)) {
-		kfree(boot_kobj);
+		kobject_put(&boot_kobj->kobj);
 		return NULL;
 	}
 	boot_kobj->data = data;