sfc: falcon: Search VPD with pci_vpd_find_ro_info_keyword()

Use pci_vpd_find_ro_info_keyword() to search for keywords in VPD to
simplify the code.

Replace netif_err() with pci_err() because the netdevice isn't registered
yet, which results in very ugly messages.

Use kmemdup_nul() instead of open-coding it.

This is the same as 37838aa4 ("sfc: Search VPD with
pci_vpd_find_ro_info_keyword()"), just for the falcon chip version.

Link: https://lore.kernel.org/r/898282a1-13bd-17bc-2e9a-d3dcd336b46c@gmail.com


Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>