vhost: Make local function static

$ make C=1 M=drivers/vhost

drivers/vhost/net.c:168:5: warning: symbol 'vhost_net_set_ubuf_info' was not declared. Should it be static?
drivers/vhost/net.c:194:6: warning: symbol 'vhost_net_vq_reset' was not declared. Should it be static?
drivers/vhost/scsi.c:219:6: warning: symbol 'tcm_vhost_done_inflight' was not declared. Should it be static?

Signed-off-by: Asias He <asias@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 5531ebc..4264840 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -216,7 +216,7 @@
 	       ((unsigned long)iov->iov_base & PAGE_MASK)) >> PAGE_SHIFT;
 }
 
-void tcm_vhost_done_inflight(struct kref *kref)
+static void tcm_vhost_done_inflight(struct kref *kref)
 {
 	struct vhost_scsi_inflight *inflight;