drbd: Remove unused conn_lowest_minor

conn_lowest_minor() last use was removed by 2011 commit
69a22773 ("drbd: Pass a peer device to a number of fuctions")

Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20241010204426.277535-1-linux@treblig.orgReviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/drbd/drbd_int.h

@@ -1364,7 +1364,6 @@ extern struct bio_set drbd_io_bio_set;
 
 extern struct mutex resources_mutex;
 
-extern int conn_lowest_minor(struct drbd_connection *connection);
 extern enum drbd_ret_code drbd_create_device(struct drbd_config_context *adm_ctx, unsigned int minor);
 extern void drbd_destroy_device(struct kref *kref);
 extern void drbd_delete_device(struct drbd_device *device);

drivers/block/drbd/drbd_main.c

@@ -471,20 +471,6 @@ void _drbd_thread_stop(struct drbd_thread *thi, int restart, int wait)
 		wait_for_completion(&thi->stop);
 }
 
-int conn_lowest_minor(struct drbd_connection *connection)
-{
-	struct drbd_peer_device *peer_device;
-	int vnr = 0, minor = -1;
-
-	rcu_read_lock();
-	peer_device = idr_get_next(&connection->peer_devices, &vnr);
-	if (peer_device)
-		minor = device_to_minor(peer_device->device);
-	rcu_read_unlock();
-
-	return minor;
-}
-
 #ifdef CONFIG_SMP
 /*
  * drbd_calc_cpu_mask() - Generate CPU masks, spread over all CPUs