Protect us from #defining linux specific ioctls in ext2_fs.h which

may be picked up by autoconfigure scripts and even used at runtime.
Found by brynet@ when building archivers/libarchive.  People agree
(at least brynet@, zhuk@, nadd6@ iirc), the only bikeshed was wether
to remote the #defines completely, used #ifdef __linux__ or #ifndef
__OpenBSD__. I choose the latter for now, because I think i've seen
some consumers of this port where some non-linux systems apparently
*do* support the same ioctls.

sysutils/e2fsprogs/Makefile

@@ -1,9 +1,9 @@
-# $OpenBSD: Makefile,v 1.36 2015/12/15 10:52:02 ajacoutot Exp $
+# $OpenBSD: Makefile,v 1.37 2016/03/28 20:08:56 kili Exp $
 
 COMMENT=	utilities to manipulate ext2 filesystems
 
 DISTNAME=	e2fsprogs-1.42.12
-REVISION=	1
+REVISION=	2
 CATEGORIES=	sysutils devel
 SHARED_LIBS=	blkid		0.0 \
 		com_err		21.0 \

sysutils/e2fsprogs/patches/patch-lib_ext2fs_ext2_fs_h

@@ -0,0 +1,19 @@
+$OpenBSD: patch-lib_ext2fs_ext2_fs_h,v 1.1 2016/03/28 20:08:56 kili Exp $
+--- lib/ext2fs/ext2_fs.h.orig	Sat Aug  2 22:26:22 2014
++++ lib/ext2fs/ext2_fs.h	Tue Mar 22 22:26:56 2016
+@@ -344,6 +344,7 @@ struct ext4_new_group_input {
+ #define _IOT_ext2_new_group_input _IOT (_IOTS(__u32), 5, _IOTS(__u16), 2, 0, 0)
+ #endif
+ 
++#ifndef __OpenBSD__
+ #define EXT2_IOC_GETFLAGS		_IOR('f', 1, long)
+ #define EXT2_IOC_SETFLAGS		_IOW('f', 2, long)
+ #define EXT2_IOC_GETVERSION		_IOR('v', 1, long)
+@@ -354,6 +355,7 @@ struct ext4_new_group_input {
+ #define EXT2_IOC_GROUP_ADD		_IOW('f', 8,struct ext2_new_group_input)
+ #define EXT4_IOC_GROUP_ADD		_IOW('f', 8,struct ext4_new_group_input)
+ #define EXT4_IOC_RESIZE_FS		_IOW('f', 16, __u64)
++#endif
+ 
+ /*
+  * Structure of an inode on the disk