Fix rev 1.12.

/tmp may not be writeable yet when dhclient is first run via
/etc/rc.d/netif so using it may not work.  Also, writing to a
predictable file in /tmp as root is a really bad idea since a malicious
user may be able to win a race and insert a symlink which will allow
them to cause any file to be overwritten.  To solve these problems,
create the tempory file in /var/run which will exist this early and is
writable only by root.

Security:	Local risk if users can cause dhclient to run on demand
		(such as by unplugging and replugging the network cable).

sbin/dhclient/dhclient-script

@@ -135,7 +135,7 @@ add_new_resolv_conf() {
 	# thus broke the script. This code creates the resolv.conf if either
 	# are provided.
 
-	local tmpres=${TMPDIR:-/tmp}/resolv.conf.std
+	local tmpres=/var/run/resolv.conf.${interface}
 	rm -f $tmpres
 
 	if [ -n "$new_domain_name" ]; then