socket-util: filter out VMADDR_CID_ANY in vsock_get_local_cid()

socket-util: filter out VMADDR_CID_ANY in vsock_get_local_cid()

It has been observed on some systems[1] that ssh-issue may print out:

 Try contacting this VM's SSH server via 'ssh vsock%4294967295' from host.

i.e. it suggests connecting with VMADDR_CID_ANY, which is not valid. It
seems that IOCTL_VM_SOCKETS_GET_LOCAL_CID may return VMADDR_CID_ANY in
some cases, e.g. when vsock is not full initialized or so.

Treat VMADDR_CID_ANY as special in vsock_get_local_cid(), the same as
VMADDR_CID_LOCAL and VMADDR_CID_HOST, and return an error.

[1] https://launchpad.net/bugs/2145027