lxc-create: check absoule path for param '--dir'
lxc-create: check absoule path for param '--dir'

Fix: #3123

Signed-off-by: qianfan Zhao <0d01fab1932da5a147025f14dd5829cf5bf10d4d@163.com>

hallyn/lxc,hallyn/lxc,hallyn/lxc