linux_inet_diag: better align listener_stats struct

Using an extra 4 bytes for the listener_stats should not
significantly increase space usage, and it has the side benefit
of making our code slightly smaller.

$ ~/linux/scripts/bloat-o-meter before.so after.so
add/remove: 0/0 grow/shrink: 1/2 up/down: 14/-32 (-18)
function                                     old     new   delta
tcp_stats                                    392     406     +14
st_to_hash                                   195     187      -8
diag                                         763     739     -24

0 files changed, 0 insertions, 0 deletions