init.rc: Allow system process to configure RNDIS USB ethernet address

Change-Id: Id339d8359e592dbc1279e423d9a5adc3a775949d
Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 247529f..11f0d09 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -188,6 +188,8 @@
 
     chown system system /sys/class/android_usb/android0/f_mass_storage/lun/file
     chmod 0660 /sys/class/android_usb/android0/f_mass_storage/lun/file
+    chown system system /sys/class/android_usb/android0/f_rndis/ethaddr
+    chmod 0660 /sys/class/android_usb/android0/f_rndis/ethaddr
 
 on boot
 # basic network init