Forbid b{copy,zero,cmp}(). Don't include <strings.h> for <string.h>

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12996

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

@@ -33,7 +33,7 @@ KERNEL_H = \
 	signal.h \
 	simd.h \
 	stat.h \
-	strings.h \
+	string.h \
 	sunddi.h \
 	sysmacros.h \
 	systeminfo.h \

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

@@ -0,0 +1 @@
+#include <linux/string.h>

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

@@ -1,30 +0,0 @@
-/*
- *  Copyright (C) 2018 Lawrence Livermore National Security, LLC.
- *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
- *  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_SYS_STRINGS_H
-#define	_SPL_SYS_STRINGS_H
-
-#include <linux/string.h>
-
-#define	bzero(ptr, size)		memset(ptr, 0, size)
-#define	bcopy(src, dest, size)		memmove(dest, src, size)
-#define	bcmp(src, dest, size)		memcmp((src), (dest), (size_t)(size))
-
-#endif	/* _SPL_SYS_STRINGS_H */