dm vdo indexer: update ASSERT and ASSERT_LOG_ONLY usage

Update indexer uses of ASSERT and ASSERT_LOG_ONLY to
VDO_ASSERT and VDO_ASSERT_LOG_ONLY, respectively. Remove
ASSERT and ASSERT_LOG_ONLY. Also rename uds_assertion_failed
to vdo_assertion_failed.

Signed-off-by: Matthew Sakai <msakai@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>