block: allow interrupting a co_sleep_ns

In the next patch we want to reenter the coroutine from
block_job_cancel_sync and cancel the timer.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

qemu-coroutine-sleep.c

@@ -23,7 +23,6 @@ static void co_sleep_cb(void *opaque)
 {
     CoSleepCB *sleep_cb = opaque;
 
-    qemu_free_timer(sleep_cb->ts);
     qemu_coroutine_enter(sleep_cb->co, NULL);
 }
 
@@ -35,4 +34,6 @@ void coroutine_fn co_sleep_ns(QEMUClock *clock, int64_t ns)
     sleep_cb.ts = qemu_new_timer(clock, SCALE_NS, co_sleep_cb, &sleep_cb);
     qemu_mod_timer(sleep_cb.ts, qemu_get_clock_ns(clock) + ns);
     qemu_coroutine_yield();
+    qemu_del_timer(sleep_cb.ts);
+    qemu_free_timer(sleep_cb.ts);
 }