enic: Bug fix: Free MSI intr with correct data handle

Bug fix: Free MSI intr with correct data handle
Use davem proposed naming for MSI-X tx/rx vectors (ethX-tx-0, ethX-rx-0)

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>