klayout: fix a potential error when MAKE_JOBS is not defined

[Ryo ONODERA <ryoon%NetBSD.org@localhost>]

Module Name:	pkgsrc-wip
Committed By:	Ryo ONODERA <ryoon%NetBSD.org@localhost>
Pushed By:	ryoon
Date:		Tue Jul 17 17:59:02 2018 +0900
Changeset:	409d6531fe5aa87601c67f61d173a24ebffb854f

Modified Files:
	klayout/Makefile

Log Message:
klayout: fix a potential error when MAKE_JOBS is not defined

To see a diff of this commit:
https://wip.pkgsrc.org/cgi-bin/gitweb.cgi?p=pkgsrc-wip.git;a=commitdiff;h=409d6531fe5aa87601c67f61d173a24ebffb854f

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

diffstat:
 klayout/Makefile | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diffs:
diff --git a/klayout/Makefile b/klayout/Makefile
index 9ed56091de..994466f1cd 100644
--- a/klayout/Makefile
+++ b/klayout/Makefile
@@ -28,14 +28,20 @@ INSTALL_BINDIR=		${DESTDIR}${PREFIX}/bin
 INSTALL_LIBDIR=		${DESTDIR}${PREFIX}/lib
 REL_DIR=		build-release
 
+.include "../../mk/bsd.prefs.mk"
+
+.if !empty(MAKE_JOBS)
+MAKE_JOBS_FLAG=		-option -j${MAKE_JOBS}
+.endif
+
 do-build:
 	cd ${WRKSRC} && ${PKGSRC_SETENV} ${MAKE_ENV} ${BASH} build.sh \
 	-python python${PYVERSSUFFIX} \
 	-qt5 \
 	-qmake ${PREFIX}/qt5/bin/qmake \
 	-ruby ${PREFIX}/bin/${RUBY_NAME} \
-	-prefix ${PREFIX} \
-	-option -j${MAKE_JOBS}
+	${MAKE_JOBS_FLAG} \
+	-prefix ${PREFIX}
 
 do-install:
 	cd ${WRKSRC} && \