virtio-blk: Drop redundant VirtIOBlock member conf Commit 12c5674 turned it into a pointer to member blk.conf. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: BenoƮt Canet <benoit.canet@nodalink.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>