CVE-2022-50086 block: don't allow the same type rq_qos add more than once

In the Linux kernel, the following vulnerability has been resolved: block: don't allow the same type rqqos add more than once In our test of iocost, we encountered some list add/del corruptions of innerwalk list in ioctimerfn. The reason can be described as follows: cpu 0 cpu 1 iocqoswrite...