Use SRCTOP-relative paths to other directories instead of .CURDIR-relative ones

This simplifies pathing in make/displayed output.

MFC after:	1 week
Sponsored by:	Dell EMC Isilon

usr.sbin/rpc.yppasswdd/Makefile

@@ -2,8 +2,8 @@
 
 RPCDIR=	${DESTDIR}/usr/include/rpcsvc
 
-.PATH: ${.CURDIR}/../../usr.sbin/ypserv ${.CURDIR}/../../usr.bin/chpass \
-       ${.CURDIR}/../../libexec/ypxfr ${RPCDIR}
+.PATH: ${SRCTOP}/usr.sbin/ypserv ${SRCTOP}/usr.bin/chpass \
+       ${SRCTOP}/libexec/ypxfr ${RPCDIR}
 
 PROG=	rpc.yppasswdd
 SCRIPTS=yppwupdate
@@ -16,9 +16,9 @@ GENSRCS=yp.h yp_clnt.c yppasswd.h yppasswd_private.h yppasswd_private_svc.c \
 
 WARNS?=	 5
 CFLAGS+= -fno-strict-aliasing
-CFLAGS+= -I${.CURDIR}/../../usr.sbin/vipw \
-	 -I${.CURDIR}/../../usr.sbin/ypserv \
-	 -I${.CURDIR}/../../libexec/ypxfr \
+CFLAGS+= -I${SRCTOP}/usr.sbin/vipw \
+	 -I${SRCTOP}/usr.sbin/ypserv \
+	 -I${SRCTOP}/libexec/ypxfr \
 	 -I${.CURDIR} -I.
 LIBADD=	rpcsvc crypt util