ip stats displays bridge-related multicast and STP stats, but not VLAN
stats. There is code for requesting, decoding and formatting these stats
accessible through `bridge -s vlan', but the `ip stats' suite lacks it. In
this patchset, extract the `bridge vlan' code to a generally accessible
place and extend `ip stats' to use it.
This reuses the existing display and JSON format, and plugs it into the
existing `ip stats' hierarchy:
# ip stats show dev v2 group xstats_slave subgroup bridge suite vlan
2: v2: group xstats_slave subgroup bridge suite vlan
10
RX: 3376 bytes 50 packets
TX: 2824 bytes 44 packets
# ip stats show dev br1 group xstats subgroup bridge suite vlan
211: br1: group xstats subgroup bridge suite vlan
10
RX: 3376 bytes 50 packets
TX: 2824 bytes 44 packets