Simplify idioms in Makefiles further

- Use SRCTOP-relative paths instead of .CURDIR-relative ones where possible
- Use :H to manipulate .CURDIR in areas instead of ..-relative paths.

MFC after:	1 week
Sponsored by:	Dell EMC Isilon

usr.sbin/ntp/libntp/Makefile

@@ -73,14 +73,14 @@ ISC_SRCS= assertions.c \
 
 SRCS=	${NTP_SRCS} ${ISC_SRCS} version.c
 
-CFLAGS+= -I${.CURDIR}/../../../contrib/ntp/include \
-	-I${.CURDIR}/../../../contrib/ntp/lib/isc/include \
-	-I${.CURDIR}/../../../contrib/ntp/lib/isc/unix/include \
-	-I${.CURDIR}/../../../contrib/ntp/lib/isc/pthreads/include \
-	-I${.CURDIR}/../../../contrib/ntp/sntp/libopts \
-	-I${.CURDIR}/../../../lib/libc/${MACHINE_ARCH} \
-	-I${.CURDIR}/../../../lib/libedit/edit \
-	-I${.CURDIR}/../ \
+CFLAGS+= -I${SRCTOP}/contrib/ntp/include \
+	-I${SRCTOP}/contrib/ntp/lib/isc/include \
+	-I${SRCTOP}/contrib/ntp/lib/isc/unix/include \
+	-I${SRCTOP}/contrib/ntp/lib/isc/pthreads/include \
+	-I${SRCTOP}/contrib/ntp/sntp/libopts \
+	-I${SRCTOP}/lib/libc/${MACHINE_ARCH} \
+	-I${SRCTOP}/lib/libedit/edit \
+	-I${.CURDIR:H} \
 	-I${.CURDIR}/
 
 CFLAGS+= -DHAVE_BSD_NICE -DHAVE_STDINT_H
@@ -88,6 +88,6 @@ CFLAGS+= -DHAVE_BSD_NICE -DHAVE_STDINT_H
 CLEANFILES+= .version version.c
 
 version.c:
-	sh -e ${.CURDIR}/../scripts/mkver ntpd
+	sh -e ${.CURDIR:H}/scripts/mkver ntpd
 
 .include <bsd.lib.mk>

usr.sbin/ntp/ntpdate/Makefile

@@ -25,6 +25,6 @@ LIBADD+=	md
 CLEANFILES+= .version version.c
 
 version.c:
-	sh -e ${.CURDIR}/../scripts/mkver ntpdate
+	sh -e ${.CURDIR:H}/scripts/mkver ntpdate
 
 .include <bsd.prog.mk>

usr.sbin/ntp/ntpdc/Makefile

@@ -30,6 +30,6 @@ LIBADD+=	md
 CLEANFILES+= .version version.c
 
 version.c:
-	sh -e ${.CURDIR}/../scripts/mkver ntpdc
+	sh -e ${.CURDIR:H}/scripts/mkver ntpdc
 
 .include <bsd.prog.mk>

usr.sbin/ntp/ntpq/Makefile

@@ -34,6 +34,6 @@ CFLAGS+=	-DHAVE_LIBEDIT -DHAVE_READLINE_READLINE_H \
 CLEANFILES+= .version version.c
 
 version.c:
-	sh -e ${.CURDIR}/../scripts/mkver ntpq
+	sh -e ${.CURDIR:H}/scripts/mkver ntpq
 
 .include <bsd.prog.mk>