CVE-2023-53464 scsi: iscsi_tcp: Check that sock is valid before iscsi_set_param()

In the Linux kernel, the following vulnerability has been resolved: scsi: iscsitcp: Check that sock is valid before iscsisetparam The validity of sock should be checked before assignment to avoid incorrect values. Commit 57569c37f0ad "scsi: iscsi: iscsitcp: Fix null-ptr-deref while calling...