jf: Remove modem links scripts

 * Create the symlinks ourselves at build time. Remounting the system
   partition to do this is just stupid.

Change-Id: I224c20af820554661fe027e5835b18cb5589c694
Fix USB Tethering

Signed-off-by: aways <aways@c-rom.org>

Change-Id: I36c862548875ecb83606871a3ebc75ab89474af0