path: drop redundant local-scope vars writes

path.c:98:2: warning: Value stored to 'len' is never read
        len -= off;
        ^      ~~~
path.c:99:2: warning: Value stored to 'path' is never read
        path += off;
        ^       ~~~

Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>