Handle WITH/WITHOUT_PF in libsysdecode

Only filter out the PF ioctls if we're building without pf support.
Until now those were always filtered out, so truss did not show symbolic
names for pf ioctls.

Differential Revision:	https://reviews.freebsd.org/D11629

lib/libsysdecode/Makefile

@@ -122,7 +122,7 @@ tables.h: mktables
 ioctl.c: .PHONY
 .endif
 ioctl.c: mkioctls .META
-	env CPP="${CPP}" \
+	env CPP="${CPP}" MK_PF="${MK_PF}" \
 	    /bin/sh ${.CURDIR}/mkioctls ${SYSROOT:U${DESTDIR}}${INCLUDEDIR} > ${.TARGET}
 
 beforedepend: ioctl.c tables.h

lib/libsysdecode/mkioctls

@@ -17,8 +17,14 @@ LC_ALL=C; export LC_ALL
 # XXX should we use an ANSI cpp?
 ioctl_includes=$(
 	cd $includedir
+
+	filter='tee'
+	if [ "${MK_PF}" == "no" ]; then
+		filter='egrep -v (net/pfvar|net/if_pfsync)\.h'
+	fi
+
 	find -H -s * -name '*.h' | \
-	egrep -v '(net/pfvar|net/if_pfsync)\.h' | \
+		$filter | \
 		xargs egrep -l \
 '^#[ 	]*define[ 	]+[A-Za-z_][A-Za-z0-9_]*[ 	]+_IO[^a-z0-9_]' |
 		awk '{printf("#include <%s>\\n", $1)}'