firmware_loader: Fix memory leak in firmware upload

In the Linux kernel, the following vulnerability has been resolved:

firmware_loader: Fix memory leak in firmware upload

In the case of firmware-upload, an instance of struct fw_upload is

allocated in firmware_upload_register(). This data needs to be freed

in fw_dev_release(). Create a new fw_upload_free() function in

sysfs_upload.c to handle the firmware-upload specific memory frees

and incorporate the missing kfree call for the fw_upload structure.