Snippets for msgpack-c 7.0.0 from Fedora ppc64le

Sourced from https://kojipkgs.fedoraproject.org/packages/msgpack-c/7.0.0/3.fc45/data/logs/ppc64le/build.log.

• /builddir/build/BUILD/msgpack-c-7.0.0-build/msgpack-c-7.0.0/test/buffer_c.cpp:126:15: warning: ignoring return value of ‘ssize_t writev(int, const iovec*, int)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
    126 |         writev(fd, iov, (int)iovcnt);
        |         ~~~~~~^~~~~~~~~~~~~~~~~~~~~~
  

• /builddir/build/BUILD/msgpack-c-7.0.0-build/msgpack-c-7.0.0/test/buffer_c.cpp:129:13: warning: ignoring return value of ‘ssize_t read(int, void*, size_t)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
    129 |         read(fd, buf, len);
        |         ~~~~^~~~~~~~~~~~~~