Remove zfs_debug.h which is a duplicate of the version in the

modules directory.  Having two copies is just asking for trouble.

lib/libspl/include/sys/zfs_debug.h

@@ -1,73 +0,0 @@
-/*
- * CDDL HEADER START
- *
- * The contents of this file are subject to the terms of the
- * Common Development and Distribution License (the "License").
- * You may not use this file except in compliance with the License.
- *
- * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
- * or http://www.opensolaris.org/os/licensing.
- * See the License for the specific language governing permissions
- * and limitations under the License.
- *
- * When distributing Covered Code, include this CDDL HEADER in each
- * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
- * If applicable, add the following below this CDDL HEADER, with the
- * fields enclosed by brackets "[]" replaced with your own identifying
- * information: Portions Copyright [yyyy] [name of copyright owner]
- *
- * CDDL HEADER END
- */
-/*
- * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
- * Use is subject to license terms.
- */
-
-#ifndef _SYS_ZFS_DEBUG_H
-#define	_SYS_ZFS_DEBUG_H
-
-#ifdef	__cplusplus
-extern "C" {
-#endif
-
-#ifndef TRUE
-#define	TRUE 1
-#endif
-
-#ifndef FALSE
-#define	FALSE 0
-#endif
-
-/*
- * ZFS debugging
- */
-
-#if defined(DEBUG) || !defined(_KERNEL)
-#define	ZFS_DEBUG
-#endif
-
-extern int zfs_flags;
-
-#define	ZFS_DEBUG_DPRINTF	0x0001
-#define	ZFS_DEBUG_DBUF_VERIFY	0x0002
-#define	ZFS_DEBUG_DNODE_VERIFY	0x0004
-#define	ZFS_DEBUG_SNAPNAMES	0x0008
-#define	ZFS_DEBUG_MODIFY	0x0010
-
-#ifdef ZFS_DEBUG
-extern void __dprintf(const char *file, const char *func,
-    int line, const char *fmt, ...);
-#define	dprintf(...) \
-	if (zfs_flags & ZFS_DEBUG_DPRINTF) \
-		__dprintf(__FILE__, __func__, __LINE__, __VA_ARGS__)
-#else
-#define	dprintf(...) ((void)0)
-#endif /* ZFS_DEBUG */
-
-extern void zfs_panic_recover(const char *fmt, ...);
-
-#ifdef	__cplusplus
-}
-#endif
-
-#endif	/* _SYS_ZFS_DEBUG_H */