module/zfs: remove zfs_zevent_console and zfs_zevent_cols

zfs_zevent_console committed multiple printk()s per line without
properly continuing them ‒ a single event could easily be fragmented
across over thirty lines, making it useless for direct application

zfs_zevent_cols exists purely to wrap the output from zfs_zevent_console

The niche this was supposed to fill can be better served by something
akin to the all-syslog ZEDLET

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #7082 
Closes #11996

include/os/linux/spl/sys/Makefile.am

@@ -6,7 +6,6 @@ KERNEL_H = \
 	callo.h \
 	cmn_err.h \
 	condvar.h \
-	console.h \
 	cred.h \
 	ctype.h \
 	debug.h \

include/os/linux/spl/sys/console.h

@@ -1,30 +0,0 @@
-/*
- *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
- *  Copyright (C) 2007 The Regents of the University of California.
- *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
- *  Written by Brian Behlendorf <behlendorf1@llnl.gov>.
- *  UCRL-CODE-235197
- *
- *  This file is part of the SPL, Solaris Porting Layer.
- *
- *  The SPL is free software; you can redistribute it and/or modify it
- *  under the terms of the GNU General Public License as published by the
- *  Free Software Foundation; either version 2 of the License, or (at your
- *  option) any later version.
- *
- *  The SPL is distributed in the hope that it will be useful, but WITHOUT
- *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- *  for more details.
- *
- *  You should have received a copy of the GNU General Public License along
- *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef	_SPL_CONSOLE_H
-#define	_SPL_CONSOLE_H
-
-#define	console_vprintf	vprintk
-#define	console_printf	printk
-
-#endif /* _SPL_CONSOLE_H */