be2net: use pci_vfs_assigned()/pci_num_vf() instead of be_find_vfs()

be_find_vfs() is no longer needed as the common PCI calls provide the same
functionality.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>