examples: Use safer names for stdin, stdout, stderr
examples: Use safer names for stdin, stdout, stderr

BUG: https://red.libssh.org/issues/168

On some platforms, like OpenBSD, stdin and friends are macros which break
compilation of this struct. I've fixed these names such that it compiles and
runs cleanly on OpenBSD

Reviewed-by: Andreas Schneider <5be00ddc76278cf6077f5047ca3384a88460c671@cryptomilk.org>

taikoo/libssh,nviennot/libssh,DouglasHeriot/libssh,taikoo/libssh,mwgoldsmith/libssh,kedazo/libssh,DouglasHeriot/libssh,Distrotech/libssh,wangshawn/libssh,pouete/libssh,pouete/libssh,kedazo/libssh,nviennot/libssh,kedazo/libssh,Distrotech/libssh,wangshawn/libssh,mwgoldsmith/ssh,Distrotech/libssh,sebadoom/libssh,wangshawn/libssh,nviennot/libssh,robxu9/libssh,pouete/libssh,sebadoom/libssh,mwgoldsmith/ssh,taikoo/libssh,mwgoldsmith/libssh,sebadoom/libssh,sebadoom/libssh,robxu9/libssh,mwgoldsmith/ssh,mwgoldsmith/ssh,nviennot/libssh,robxu9/libssh,kedazo/libssh,taikoo/libssh,DouglasHeriot/libssh,robxu9/libssh,Distrotech/libssh,DouglasHeriot/libssh,mwgoldsmith/libssh,pouete/libssh,mwgoldsmith/libssh,wangshawn/libssh