Revert "zpool reopen should detect expanded devices"

This reverts commit 2a16d4cfaf.

The commit was causing a "attempt to access beyond the end
of device" error:

list.zfsonlinux.org/pipermail/zfs-discuss/2018-September/032217.html

lib/libzfs/libzfs_pool.c

@@ -22,7 +22,7 @@
 /*
  * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2018 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2014 by Delphix. All rights reserved.
  * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
  * Copyright (c) 2017 Datto Inc.
  */
@@ -42,7 +42,6 @@
 #include <sys/efi_partition.h>
 #include <sys/vtoc.h>
 #include <sys/zfs_ioctl.h>
-#include <sys/vdev_disk.h>
 #include <dlfcn.h>
 
 #include "zfs_namecheck.h"
@@ -935,6 +934,17 @@ zpool_prop_get_feature(zpool_handle_t *zhp, const char *propname, char *buf,
 	return (0);
 }
 
+/*
+ * Don't start the slice at the default block of 34; many storage
+ * devices will use a stripe width of 128k, other vendors prefer a 1m
+ * alignment.  It is best to play it safe and ensure a 1m alignment
+ * given 512B blocks.  When the block size is larger by a power of 2
+ * we will still be 1m aligned.  Some devices are sensitive to the
+ * partition ending alignment as well.
+ */
+#define	NEW_START_BLOCK		2048
+#define	PARTITION_END_ALIGNMENT	2048
+
 /*
  * Validate the given pool name, optionally putting an extended error message in
  * 'buf'.