hfsc: reduce hfsc_sched to 14 cachelines

hfsc_sched is huge (size: 920, cachelines: 15), but we can get it to 14
cachelines by placing level after filter_cnt (covering 4 byte hole) and
reducing period/nactive/flags to u32 (period is just a counter,
incremented when class becomes active -- 2**32 is plenty for this
purpose, also, long is only 32bit wide on 32bit platforms anyway).

cl_vtperiod is exported to userspace via tc_hfsc_stats, but its period
member is already u32, so no precision is lost there either.

Cc: Michal Soltys <soltys@ziu.info>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>