use sysconfdir, no need for an additional confdir variable

configure.in

@@ -19,7 +19,6 @@ dnl ===========================
 AC_INIT(strongSwan,4.3.5)
 AM_INIT_AUTOMAKE(tar-ustar)
 AC_CONFIG_MACRO_DIR([m4/config])
-AC_SUBST(confdir, '${sysconfdir}')
 PKG_PROG_PKG_CONFIG
 
 dnl =================================

src/charon/plugins/eap_sim/Makefile.am

@@ -2,7 +2,7 @@
 INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/charon
 
 AM_CFLAGS = -rdynamic \
-	-DIPSEC_CONFDIR=\"${confdir}\" \
+	-DIPSEC_CONFDIR=\"${sysconfdir}\" \
 	-DSIM_READER_LIB=\"${sim_reader}\"
 
 plugin_LTLIBRARIES = libstrongswan-eapsim.la

src/charon/plugins/eap_sim_file/Makefile.am

@@ -1,7 +1,7 @@
 
 INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/charon
 
-AM_CFLAGS = -rdynamic -DIPSEC_CONFDIR=\"${confdir}\"
+AM_CFLAGS = -rdynamic -DIPSEC_CONFDIR=\"${sysconfdir}\"
 
 plugin_LTLIBRARIES = libstrongswan-eapsim-file.la
 

src/charon/plugins/stroke/Makefile.am

@@ -3,7 +3,7 @@ INCLUDES = -I$(top_srcdir)/src/libstrongswan -I$(top_srcdir)/src/charon -I$(top_
 
 AM_CFLAGS = \
 -rdynamic \
--DIPSEC_CONFDIR=\"${confdir}\" \
+-DIPSEC_CONFDIR=\"${sysconfdir}\" \
 -DIPSEC_PIDDIR=\"${piddir}\"
 
 plugin_LTLIBRARIES = libstrongswan-stroke.la

src/openac/Makefile.am

@@ -4,7 +4,7 @@ dist_man_MANS = openac.8
 
 INCLUDES = -I$(top_srcdir)/src/libstrongswan
 AM_CFLAGS = \
-  -DIPSEC_CONFDIR=\"${confdir}\" \
+  -DIPSEC_CONFDIR=\"${sysconfdir}\" \
   -DSTRONGSWAN_CONF=\"${strongswan_conf}\" \
   -DIPSEC_PLUGINDIR=\"${plugindir}\" \
   -DPLUGINS=\""${libstrongswan_plugins}\""

src/pluto/Makefile.am

@@ -65,7 +65,7 @@ INCLUDES = \
 
 AM_CFLAGS = \
 -DIPSEC_DIR=\"${ipsecdir}\" \
--DIPSEC_CONFDIR=\"${confdir}\" \
+-DIPSEC_CONFDIR=\"${sysconfdir}\" \
 -DIPSEC_PIDDIR=\"${piddir}\" \
 -DSHARED_SECRETS_FILE=\"${confdir}/ipsec.secrets\" \
 -DIPSEC_PLUGINDIR=\"${plugindir}\" \

src/scepclient/Makefile.am

@@ -16,7 +16,7 @@ INCLUDES = \
 -I$(WHACKDIR)
 
 AM_CFLAGS = \
--DIPSEC_CONFDIR=\"${confdir}\" \
+-DIPSEC_CONFDIR=\"${sysconfdir}\" \
 -DIPSEC_PLUGINDIR=\"${plugindir}\" \
 -DPLUGINS=\""${pluto_plugins}\"" \
 -DSTRONGSWAN_CONF=\"${strongswan_conf}\" \

src/starter/Makefile.am

@@ -15,7 +15,7 @@ INCLUDES = \
 
 AM_CFLAGS = \
 -DIPSEC_DIR=\"${ipsecdir}\" \
--DIPSEC_CONFDIR=\"${confdir}\" \
+-DIPSEC_CONFDIR=\"${sysconfdir}\" \
 -DIPSEC_PIDDIR=\"${piddir}\" \
 -DIPSEC_EAPDIR=\"${eapdir}\" \
 -DDEV_RANDOM=\"${random_device}\" \