bcachefs: ec: Fix a lost wakeup

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/ec.c

@@ -1146,6 +1146,7 @@ static void ec_stripe_create(struct ec_stripe_new *s)
 	mutex_lock(&c->ec_stripe_new_lock);
 	list_del(&s->list);
 	mutex_unlock(&c->ec_stripe_new_lock);
+	wake_up(&c->ec_stripe_new_wait);
 
 	ec_stripe_buf_exit(&s->existing_stripe);
 	ec_stripe_buf_exit(&s->new_stripe);