Pass the idea of the make(1) binary to use down to newvers.sh.

This is necessary so source upgrades use the correct binary.

MFC after:	3 days

For the record: Problem spotted by Scott Long, who mentioned
that source upgrades from 4.7 to recent 5.x and 6.0 are broken.
Detailed analysis shows that 4.7 has a broken make(1) binary.
A breakage was fixed in RELENG_4 in make/main.c,v 1.35.2.7 by
imp@, though the commit log erroneously stated "MFC 1.68"
while in fact it should have been spelled as "MFC 1.67".

include/Makefile

@@ -64,7 +64,7 @@ osreldate.h:	${.CURDIR}/../sys/conf/newvers.sh \
 		${.CURDIR}/Makefile
 	@${ECHO} creating osreldate.h from newvers.sh
 	@setvar PARAMFILE ${.CURDIR}/../sys/sys/param.h; \
-	. ${.CURDIR}/../sys/conf/newvers.sh;			\
+	MAKE=${MAKE} . ${.CURDIR}/../sys/conf/newvers.sh;	\
 	echo "$$COPYRIGHT" > osreldate.h;			\
 	echo "#ifdef _KERNEL" >> osreldate.h;			\
 	echo '#error "<osreldate.h> cannot be used in the kernel, use <sys/param.h>"' >> osreldate.h; \

sys/conf/kern.post.mk

@@ -221,7 +221,7 @@ majors.c: $S/conf/majors $S/conf/majors.awk
 	${AWK} -f $S/conf/majors.awk $S/conf/majors > ${.TARGET}
 
 vers.c: $S/conf/newvers.sh $S/sys/param.h ${SYSTEM_DEP}
-	sh $S/conf/newvers.sh ${KERN_IDENT}
+	MAKE=${MAKE} sh $S/conf/newvers.sh ${KERN_IDENT}
 
 vnode_if.c: $S/tools/vnode_if.awk $S/kern/vnode_if.src
 	${AWK} -f $S/tools/vnode_if.awk $S/kern/vnode_if.src -c

sys/conf/newvers.sh

@@ -82,7 +82,7 @@ fi
 
 touch version
 v=`cat version` u=${USER-root} d=`pwd` h=${HOSTNAME-`hostname`} t=`date`
-i=`make -V KERN_IDENT`
+i=`${MAKE:-make} -V KERN_IDENT`
 cat << EOF > vers.c
 $COPYRIGHT
 char sccspad[32 - 4 /* sizeof(sccs) */] = { '\\0' };