loader: GELI encrypted disk should still use device name disk

geli_probe_and_attach() does pick geli_devsw structure for
encrypted disks, the implementation depends on device
name "disk" when device type is DEVT_DISK, but geli_devsw is
setting name field "gelidisk".

PR:		264282
Submitted by:	yamagi@yamagi.org
Reported by:	yamagi@yamagi.org
MFC after:	2 weeks

stand/libsa/geli/gelidev.c

@@ -53,7 +53,7 @@ static void geli_dev_cleanup(void);
  * geli_devdesc, effectively routing all IO operations through our code.
  */
 static struct devsw geli_devsw = {
-	.dv_name     = "gelidisk",
+	.dv_name     = "disk",
 	.dv_type     = DEVT_DISK,
 	.dv_init     = geli_dev_init,
 	.dv_strategy = geli_dev_strategy,