lxc-create: bugfixes and small improvements
lxc-create: bugfixes and small improvements

- call lxc_container_put() before we exit()
- reorder includes
- use EXIT_FAILURE and EXIT_SUCCESS macros

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

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