further clean up OS differences in makefiles

No need for if() logic.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

conf.d/Makefile

@@ -1,5 +1,6 @@
 DIR=	${CONFDIR}
-CONF=	bootmisc fsck hostname localmount network staticroute urandom
+CONF=	bootmisc fsck hostname localmount network staticroute urandom \
+	${CONF-${OS}}
 
 TARGETS+=	network staticroute
 CLEANFILES+=	network staticroute
@@ -7,22 +8,16 @@ CLEANFILES+=	network staticroute
 MK=	../mk
 include ${MK}/os.mk
 
-ifeq (${OS},FreeBSD)
-CONF+=	ipfw moused powerd rarpd savecore syscons
-else ifeq (${OS},Linux)
-CONF+=	consolefont dmesg hwclock keymaps killprocs modules
-SOS=	Linux
-else ifeq (${OS},NetBSD)
-CONF+=	moused rarpd savecore
-endif
+CONF-FreeBSD=	ipfw moused powerd rarpd savecore syscons
+
+CONF-Linux=	consolefont dmesg hwclock keymaps killprocs modules
+
+CONF-NetBSD=	moused rarpd savecore
 
 include ${MK}/scripts.mk
 
-SOS?=	BSD
+network: network.in network${SFX}
+	cat $^ > $@
 
-network: network.in network.${SOS}
-	cp $@.in $@
-	[ -e $@.${SOS} ] && cat $@.${SOS} >> $@ || true
-
-staticroute: staticroute.${SOS}
-	cp $@.${SOS} $@
+staticroute: staticroute${SFX}
+	cp $@${SFX} $@