vhost: use loop instead of goto
vhost: use loop instead of goto

This patch reorder the code a bit to use loop instead of goto.
Besides, remove abudant check 'fd != -1'.

Signed-off-by: Huawei Xie <3b3be4428106761300a2ee559c9f71ecdb091553@intel.com>
Acked-by: Konstantin Ananyev <cbd5212b59ab42a210d72992d23a3aa17cfd3eaf@intel.com>

phermansson/dpdk,phermansson/dpdk,phermansson/dpdk,phermansson/dpdk