acrn-dm runs to segmentation fault when failed to create VMs with
improper parameters.
If vdevs failed to be created, they are still be freed in deinit(),
and dereference the null pointers leads to segfault.
Signed-off-by: Xinyun Liu <xinyun.liu@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>