hw/vfio/pci-quirks: Sanitize capability pointer

Coverity reports a tained scalar when traversing the capabilities
chain (CID 1516589).  In practice I've never seen a device with a
chain so broken as to cause an issue, but it's also pretty easy to
sanitize.

Fixes: f6b30c1984f7 ("hw/vfio/pci-quirks: Support alternate offset for GPUDirect Cliques")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
1 file changed