Snippets for a2jmidid 9 from Alpine x86

Sourced from https://build.alpinelinux.org/buildlogs/build-edge-x86/testing/a2jmidid/a2jmidid-9-r3.log.

• ../jack.c:64:18: warning: variable 'now' set but not used [-Wunused-but-set-variable]
     64 |   jack_nframes_t now;
        |                  ^~~
  

• ../jack.c:326:7: warning: variable 'err' set but not used [-Wunused-but-set-variable]
    326 |   int err;
        |       ^~~