- fix build on bento.

It works fine when PORTSDIR points at the physical lcoation.
if PORTSDIR point to symlink (as on benot), the workdirs are
at a diffrent location.

You expect:
${WRKDIRPREFIX}${PORTSDIR}/news/cnews/work

===>   c-nocem-3.7 depends on file: /tmp/usr/ports/news/cnews/work/conf/substitutions - not found
but the port genarted itws workfiles at:
	/tmp/a/ports/news/cnews/work/conf/substitutions

The location can only be found with
${WRKDIRPREFIX}${.CURDIR}/../../news/cnews/work

news/c-nocem/Makefile

@@ -19,7 +19,9 @@ BUILD_DEPENDS+=	${LOCALBASE}/lib/libcnews.a:${PORTSDIR}/${CNEWSSRC} \
 
 WRKSRC=		${WRKDIR}/c-nocem
 CNEWSSRC?=	news/cnews
-CNEWSWRK?=	${WRKDIRPREFIX}${PORTSDIR}/${CNEWSSRC}/work
+#CNEWSWRK?=	${WRKDIRPREFIX}${PORTSDIR}/${CNEWSSRC}/work
+# ${.CURDIR}/../.. can be diffrent from ${PORTSDIR}
+CNEWSWRK?=	${WRKDIRPREFIX}${.CURDIR}/../../${CNEWSSRC}/work
 NEWSBIN?=	${PREFIX}/libexec/cnews
 USE_GMAKE=	yes
 GNU_CONFIGURE=	yes