af_vsock: rename variables in receive loop

Record is supported via MSG_EOR flag, while current logic operates
with message, so rename variables from 'record' to 'message'.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210903123306.3273757-1-arseny.krasnov@kaspersky.com


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>