UAPI: ndctl: Remove use of PAGE_SIZE

The macro PAGE_SIZE isn't valid outside of the kernel, so it should not
appear in UAPI headers.

Furthermore, the actual machine page size could theoretically change from
an application's point of view if it's running in a container that gets
migrated to another machine (say 4K/ppc64 to 64K/ppc64).

Fixes: f2ba5a5b ("libnvdimm, namespace: make min namespace size 4K")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

include/linux/ndctl.h

+/*
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU Lesser General Public License,
+ * version 2.1, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
+ * more details.
+ */
+#ifndef _LINUX_NDCTL_H
+#define _LINUX_NDCTL_H
+
+#include <uapi/linux/ndctl.h>
+
+enum {
+	ND_MIN_NAMESPACE_SIZE = PAGE_SIZE,
+};
+
+#endif /* _LINUX_NDCTL_H */

include/uapi/linux/ndctl.h

@@ -202,10 +202,6 @@ enum nd_driver_flags {
 	ND_DRIVER_DAX_PMEM	  = 1 << ND_DEVICE_DAX_PMEM,
 };
 
-enum {
-	ND_MIN_NAMESPACE_SIZE = PAGE_SIZE,
-};
-
 enum ars_masks {
 	ARS_STATUS_MASK = 0x0000FFFF,
 	ARS_EXT_STATUS_SHIFT = 16,