net/bonding: allow configuring jumbo frames without slaves

net/bonding: allow configuring jumbo frames without slaves

Currently, 'rte_eth_dev_configure' fails on attempt to setup
max_rx_pkt_len > 2048 if no slaves was added to bonded device.

For example:

	rte_eth_dev_attach("eth_bond0,slave=05:00.0,mode=l34", &id)
	conf.rxmode.jumbo_frame = 1;
	conf.rxmode.max_rx_pkt_len = 9000;
	rte_eth_dev_configure(id, 1, 1, &conf)

Result:
	EAL: Initializing pmd_bond for eth_bond0
	EAL: Create bonded device eth_bond0 on port 4 in mode 2 on socket 0.
	rte_eth_dev_configure: ethdev port_id=4 \
		max_rx_pkt_len 9018 > max valid value 2048

It's expected that slaves will be added to bonded device inside
'rte_eth_dev_configure' and proper 'max_rx_pktlen' configured
for all of them.

Failure happens because of hardcoded low value of 'max_rx_pktlen'.
Increasing of this value to ETHER_MAX_JUMBO_FRAME_LEN will allow
above scenario (attach + configure).

It is important because it is the way OVS wants to work with
all DPDK devices (including virtual).
Changing the default hardcoded value makes no harm because
all the slaves' related code uses only 'candidate_max_rx_pktlen'
variable.

Fixes: 6cfc6a4f0d61 ("net/bonding: inherit maximum Rx packet length")
CC: stable@dpdk.org
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Reviewed-by: Eric Kinzie <ehkinzie@gmail.com>
Acked-by: Declan Doherty <declan.doherty@intel.com>