vDPA/ifcvf: remove the version number string

This commit removes the version number string, using kernel
version is enough.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210317094933.16417-5-lingshan.zhu@intel.com


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