channels: Fix possible infinite loop in channel_read().
channels: Fix possible infinite loop in channel_read().

mwgoldsmith/libssh,wangshawn/libssh,bigcat26/libssh-mod,mwgoldsmith/libssh,Distrotech/libssh,robxu9/libssh,nviennot/libssh,mwgoldsmith/libssh,taikoo/libssh,nviennot/libssh,mwgoldsmith/libssh,DouglasHeriot/libssh,jt1/honeypot-libssh,taikoo/libssh,nviennot/libssh,sebadoom/libssh,pouete/libssh,robxu9/libssh,bigcat26/libssh-mod,taikoo/libssh,kedazo/libssh,taikoo/libssh,bigcat26/libssh-mod,elastichosts/libssh,DouglasHeriot/libssh,elastichosts/libssh,Distrotech/libssh,DouglasHeriot/libssh,wangshawn/libssh,sebadoom/libssh,pouete/libssh,bigcat26/libssh-mod,robxu9/libssh,pouete/libssh,mwgoldsmith/ssh,robxu9/libssh,wangshawn/libssh,Distrotech/libssh,mwgoldsmith/ssh,jt1/honeypot-libssh,nviennot/libssh,wangshawn/libssh,kedazo/libssh,kedazo/libssh,kedazo/libssh,elastichosts/libssh,jt1/honeypot-libssh,sebadoom/libssh,pouete/libssh,sebadoom/libssh,DouglasHeriot/libssh,jt1/honeypot-libssh,Distrotech/libssh,mwgoldsmith/ssh,mwgoldsmith/ssh