Force -DFREEBSD_AOUT incase ldconfig is being compiled under elf.

Without this, <link.h> defines stuff for elf linking which is not
what ldconfig needs.

sbin/ldconfig/Makefile

@@ -1,9 +1,9 @@
-#	$Id: Makefile,v 1.11 1997/06/29 21:40:54 bde Exp $
+#	$Id: Makefile,v 1.12 1998/06/01 13:58:19 peter Exp $
 
 PROG=	ldconfig
 SRCS=	ldconfig.c shlib.c support.c
 LDDIR?= ${.CURDIR}/../../libexec/rtld-aout
-CFLAGS+=-I${LDDIR}
+CFLAGS+=-I${LDDIR} -DFREEBSD_AOUT
 MAN8=	ldconfig.8
 
 .PATH: ${LDDIR}