examples/vhost: fix path allocation failure handling
examples/vhost: fix path allocation failure handling

Add the missing failure handling for path allocation,
as realloc() may fail.

Fixes: ad0eef4d2203 ("examples/vhost: support multiple socket files")
Cc: stable@dpdk.org

Signed-off-by: Tiwei Bie <f338cf29d7d69ff1bc99f755ebfb0eb0accd409e@intel.com>
Reviewed-by: Maxime Coquelin <9a2667dee3b90866bbc9c2696cff2b7d5616c95a@redhat.com>

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