net: ti: fix UAF in tlan_remove_one

priv is netdev private data and it cannot be
used after free_netdev() call. Using priv after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() at the end of the
function.

Fixes: 1e0a8b13 ("tlan: cancel work at remove path")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>