To use eap tls, 'tmpdir' must be created before server starts.
This 'tmpdir' is used to store and verify client certificate,
and therefore radiusd do 'chmod go-rwx'.

If 'tmpdir' does NOT exists, server failed to start and default
'tmpdir' is '/tmp/radiusd'. So init script MUST create default
'tmpdir' like other directories.

Signed-off-by: Eiji MATSUMOTO <toudaiman@gmail.com>