Set WFORMAT=0, because our compiler currently complains about NULL

arg 2 to err() and friends, and warnings are promoted to errors.

This allows the following revisions to be reverted:

	rev 1.39	src/bin/cp/cp.c
	rev 1.26	src/bin/chmod/chmod.c
	rev 1.40	src/bin/rm/rm.c

The following revisions can already be reverted, because they were
already covered by WFORMAT=0:

	rev 1.8		src/bin/ls/lomac.c
	rev 1.63	src/bin/ls/ls.c
	rev 1.8		src/bin/ps/lomac.c
	rev 1.34	src/bin/rcp/rcp.c

bin/chmod/Makefile

@@ -2,5 +2,6 @@
 # $FreeBSD$
 
 PROG=	chmod
+WFORMAT=0
 
 .include <bsd.prog.mk>

bin/cp/Makefile

@@ -4,5 +4,6 @@
 PROG=	cp
 SRCS=	cp.c utils.c
 CFLAGS+= -DVM_AND_BUFFER_CACHE_SYNCHRONIZED
+WFORMAT=0
 
 .include <bsd.prog.mk>

bin/rm/Makefile

@@ -3,6 +3,7 @@
 
 PROG=	rm
 SRCS=	rm.c
+WFORMAT=0
 
 LINKS=	${BINDIR}/rm ${BINDIR}/unlink
 MLINKS=	rm.1 unlink.1