Fix deprecated syntax

coprocess.cc:143:24: warning: use of GNU old-style field designator extension [-Wgnu-designator]
        struct timeval tv={tv_sec: d_timeout/1000, tv_usec: (d_timeout % 1000) * 1000,};
                           ^~~~~~~
                           .tv_sec =
coprocess.cc:143:48: warning: use of GNU old-style field designator extension [-Wgnu-designator]
        struct timeval tv={tv_sec: d_timeout/1000, tv_usec: (d_timeout % 1000) * 1000,};
                                                   ^~~~~~~~
                                                   .tv_usec =
2 warnings generated.
Remove a few unused variables