The maxsegsz of a dma tag created in de(4) is TULIP_DATA_PER_DESC bytes.
In Rx path it allocates a new mbuf with m_getcl(9) so the length of
the mbuf is MCLBYTES which is greater than a segment size specified by
the dma tag. This segment size mismatch caused a voluntary panic.
Fix the panic by settting the mbuf length to TULIP_DATA_PER_DESC.
Reported by: Arne H Juul <arnej AT yahoo-inc DOT com>
Tested by: Arne H Juul <arnej AT yahoo-inc DOT com>