examples/vhost: support multiple socket files
examples/vhost: support multiple socket files

When examples/vhost runs in client mode, only one QEMU can be connected.
This is because that examples/vhost just supports one socket file. This
patch is to add multiple sockets support for examples/vhost.

Signed-off-by: Jiayu Hu <32e4f0527a0c8fd19a4086e4191a246becffadac@intel.com>
Acked-by: Yuanhan Liu <5dcef21195e64c9c08aa779bb62b25e9133eaa33@linux.intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk