change hotplug trigger to a simpler awk command

git-svn-id: svn://svn.openwrt.org/openwrt/branches/buildroot-ng/openwrt@4685 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/base-files/default/etc/init.d/S10boot

@@ -17,7 +17,8 @@ touch /var/log/wtmp
 touch /var/log/lastlog
 [ "$FAILSAFE" = "true" ] && touch /tmp/.failsafe
 
-for iface in $(/sbin/ifconfig -a | awk '{print $1}' | grep eth); do
+# manually trigger hotplug before loading modules
+for iface in $(awk -F: '/:/ {print $1}' /proc/net/dev); do
 	/usr/bin/env -i ACTION=add INTERFACE="$iface" /sbin/hotplug net
 done