sched/deadline: Fix replenish_dl_new_period dl_server condition

The condition in replenish_dl_new_period() that checks if a reservation
(dl_server) is deferred and is not handling a starvation case is
obviously wrong.

Fix it.

Fixes: a110a81c ("sched/deadline: Deferrable dl server")
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20241127063740.8278-1-juri.lelli@redhat.com