net: rps: move received_rps field to a better location

Commit 14d898f3

 ("dev: Move received_rps counter next
to RPS members in softnet data") was unfortunate:

received_rps is dirtied by a cpu and never read by other
cpus in fast path.

Its presence in the hot RPS cache line (shared by many cpus)
is hurting RPS/RFS performance.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>