fix lxc_console_cb_tty_*()
fix lxc_console_cb_tty_*()

Clean exit when read() == -1 && errno != EINTR or read() == 0.

Signed-off-by: Christian Brauner <48455ab3070520a2d174545c7239d6d0fabd9a83@mailbox.org>

QingweiPeterLan/cs188-lxc,ss1h2a3tw/lxc,akshaykarle/lxc,cjwatson/lxc,hfuCN/lxc,caglar10ur/lxc,caglar10ur/lxc,ss1h2a3tw/lxc,federicobriata/lxc,aeris/lxc,terceiro/lxc,QingweiPeterLan/cs188-lxc,ysbnim/lxc,thmo/lxc,aeris/lxc,QingweiPeterLan/cs188-lxc,ysbnim/lxc,ss1h2a3tw/lxc,terceiro/lxc,aeris/lxc,LynxChaus/lxc,federicobriata/lxc,hallyn/lxc,ysbnim/lxc,caglar10ur/lxc,LynxChaus/lxc,hfuCN/lxc,federicobriata/lxc,hfuCN/lxc,akshaykarle/lxc,LynxChaus/lxc,cjwatson/lxc,thmo/lxc,thmo/lxc,cjwatson/lxc,GreatFruitOmsk/lxc,akshaykarle/lxc,GreatFruitOmsk/lxc,terceiro/lxc,hallyn/lxc,GreatFruitOmsk/lxc,hallyn/lxc