net/failsafe: fix reported device info

net/failsafe: fix reported device info

The failsafe driver device info had several issues in the
info it reported in dev_info_get:
  - it cleared dev_info->device set in rte_eth_dev_info_get
  - many fields (for example max_rx_queue) should be the minimum
    of all sub devices
  - it reported tx capa for the active transmit device, but
    the device may change.

There was enough messed up that ended up reworking the info_get
handler. There is no need to save current values or have a
template for defaults.

Fixes: 4e31ee26ed51 ("net/failsafe: report actual device capabilities")
Cc: stable@dpdk.org
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Acked-by: Gaetan Rivet <gaetan.rivet@6wind.com>