CVE-2022-50133 usb: xhci_plat_remove: avoid NULL dereference

In the Linux kernel, the following vulnerability has been resolved: usb: xhciplatremove: avoid NULL dereference Since commit 4736ebd7fcaff1eb8481c140ba494962847d6e0a "usb: host: xhci-plat: omit shared hcd if either root hub has no ports" xhci-sharedhcd can be NULL, which causes the following Oops...