Fix bug in NFC host coverage code.

Change self._dut to self.dut so that coverage initializes properly on
host-driven nfc test.

Test: make vts; vts-tradefed run commandAndExit vts -m
VtsHalNfcV1_0HostBinderize
Bug: 62925298

Change-Id: I55661dccc7abbb1788f6a58102314c086e50a180
1 file changed