qdisc: fix build with !CONFIG_NET_SCHED

Multiqueue scheduler refers to default_qdisc_ops; therefore the
variable definition needs to be moved to handle case where net
scheduler API is not available.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc net/sched/sch_api.c
Simple merge

diff --cc net/sched/sch_generic.c
Simple merge