The mac address usually write in factory block. but sometime user erase this block , the mac address will change to ff:ff:ff:ff:ff:ff.
This patch is purpose to fix this issue.
Signed-off-by: wengbj <linux.c@foxmail.com>
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@44166 3c298f89-4303-0410-b956-a3cf2f4a3e73