fix for tty-serial-move-port

Hi Alan

next-20081204 crashes with the following message:

BUG: unable to handle kernel paging request at ffff88007d320248
IP: [<ffffffff803de934>] uart_remove_one_port+0xef/0x111
                kfree(info);
     393:       49 8d 7d 10             lea    0x10(%r13),%rdi
     397:       e8 00 00 00 00          callq  39c <uart_remove_one_port+0xef>

Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>