Remove references to systemd-sysv-convert

Packaging guidelines have been amended to not require systemd for scriptlets,
see https://docs.fedoraproject.org/en-US/packaging-guidelines/Scriptlets/#_scriptlets.

The comment duplicates what the macro contains.

systemd-sysv-convert binary was removed in 2013, trying to call it is
unlikely to succeed.

chkconfig binary is provided by the chkconfig package, which is not in
Requires. (And makes little sense to call nowadays anyway.)

kexec-tools.spec

@@ -60,9 +60,6 @@ Source109: dracut-early-kdump-module-setup.sh
 Source200: dracut-fadump-init-fadump.sh
 Source201: dracut-fadump-module-setup.sh
 
-Requires(post): systemd-units
-Requires(preun): systemd-units
-Requires(postun): systemd-units
 Requires(pre): coreutils sed zlib
 Requires: dracut >= 050
 Requires: dracut-network >= 050
@@ -72,7 +69,7 @@ Requires: grubby
 BuildRequires: make
 BuildRequires: zlib-devel elfutils-devel glib2-devel bzip2-devel ncurses-devel bison flex lzo-devel snappy-devel
 BuildRequires: pkgconfig intltool gettext
-BuildRequires: systemd-units
+BuildRequires: systemd-rpm-macros
 BuildRequires: automake autoconf libtool
 %ifarch %{ix86} x86_64 ppc64 ppc s390x ppc64le
 Obsoletes: diskdumputils netdump kexec-tools-eppic
@@ -292,20 +289,8 @@ fi
 %systemd_postun_with_restart kdump.service
 
 %preun
-# Package removal, not upgrade
 %systemd_preun kdump.service
 
-%triggerun -- kexec-tools < 2.0.2-3
-# Save the current service runlevel info
-# User must manually run systemd-sysv-convert --apply kdump
-# to migrate them to systemd targets
-/usr/bin/systemd-sysv-convert --save kdump >/dev/null 2>&1 ||:
-
-# Run these because the SysV package being removed won't do them
-/sbin/chkconfig --del kdump >/dev/null 2>&1 || :
-/bin/systemctl try-restart kdump.service >/dev/null 2>&1 || :
-
-
 %triggerin -- kernel-kdump
 touch %{_sysconfdir}/kdump.conf