fix ${pf} variable so that the special pflogd check works; ok deraadt@

src/etc/rc.conf

@@ -1,6 +1,6 @@
 #!/bin/sh -
 #
-#	$OpenBSD: rc.conf,v 1.156 2011/07/11 05:50:05 robert Exp $
+#	$OpenBSD: rc.conf,v 1.157 2011/07/17 16:35:58 david Exp $
 
 # set these to "NO" to turn them off.  otherwise, they're used as flags
 ldpd_flags=NO		# for normal use: ""
@@ -130,7 +130,7 @@ fi
 
 # special care needed for pflogd to avoid starting it up and failing
 # if pf is not enabled
-if [ X"${PF}" = X"NO" ]; then
+if [ X"${pf}" = X"NO" ]; then
 	pflogd_flags=NO
 fi