CVE-2026-72329: net/liquidio: drop cached VF pci_dev LUT

In the Linux kernel, the following vulnerability has been resolved:

net/liquidio: drop cached VF pcidev LUT

The PF SR-IOV enable path caches VF pcidev pointers in dpiringtovfpcidevlut[] by iterating with pcigetdevice(). Those entries do not own a reference, because the iterator drops the previous device reference on each step. The cached pointer is then dereferenced later when handling OCTEONVFFLRREQUEST.

Replace the cached VF mapping with runtime lookup on the mailbox DPI ring: derive the VF index from qno, resolve the VF via exported PCI IOV helpers, validate it with the PF pointer and VF ID, then issue pcieflr() and drop the reference with pcidevput(). Remove the unused VF lookup table initialization and cleanup.