ip: promote missed packets to the -s row

ip: promote missed packets to the -s row

missed_packet_errors are much more commonly reported:

linux$ git grep -c '[.>]rx_missed_errors ' -- drivers/ | wc -l
64
linux$ git grep -c '[.>]rx_over_errors ' -- drivers/ | wc -l
37

Plus those drivers are generally more modern than those
using rx_over_errors.

Since recently merged kernel documentation makes this
preference official, let's make ip -s output more informative
and let rx_missed_errors take the place of rx_over_errors.

Before:

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:0a:f7:c1:4d:38 brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast
    6.04T      4.67G    0       0       0       67.7M
    RX errors: length   crc     frame   fifo    missed
               0        0       0       0       7
    TX: bytes  packets  errors  dropped carrier collsns
    3.13T      2.76G    0       0       0       0
    TX errors: aborted  fifo   window heartbeat transns
               0        0       0       0       6

After:

2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
    link/ether 00:0a:f7:c1:4d:38 brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped missed  mcast
    6.04T      4.67G    0       0       7       67.7M
    RX errors: length   crc     frame   fifo    overrun
               0        0       0       0       0
    TX: bytes  packets  errors  dropped carrier collsns
    3.13T      2.76G    0       0       0       0
    TX errors: aborted  fifo   window heartbeat transns
               0        0       0       0       6

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David Ahern <dsahern@gmail.com>