The usb_storage tests report couple of errors, says:
* missing blk_extra_params_stg
* Expected: '520fa169-32f8-431f-9f1e-70992671d2e5', Actual: 'TARGET_DISK0'
('520fa169-..' is generated dynamically, 'TARGET_..' is my blk_extra_params_stg)
* Can not get drive path by id 'NO_EQUAL_STRING
* Can not get drive path by id 'EMPTY_STRING'

This patch fixes above issues.
Signed-off-by: NLin Ma <lma@suse.com>