CVE-2023-52617 PCI: switchtec: Fix stdev_release() crash after surprise hot remove

In the Linux kernel, the following vulnerability has been resolved: PCI: switchtec: Fix stdevrelease crash after surprise hot remove A PCI device hot removal may occur while stdev-cdev is held open. The call to stdevrelease then happens during close or exit, at a point way past switchtecpciremove...