kernel: pvrusb2: fix use after free on context disconnection
JIRA: https://issues.redhat.com/browse/RHEL-27529
CVE: CVE-2023-52445
BUILD INFO: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=59757836
FUNCTIONAL TESTING: QA
DESCRIPTION: This fixes a possible invalid read within the context disconnection call stack, which can be triggered due to a syncronization issue between the usb hub_event handler and the pvrusb2 driver.
Signed-off-by: Desnes Nunes desnesn@redhat.com