tests/kms_cursor_crc: Combine data_t and test_data_t

tests/kms_cursor_crc: Combine data_t and test_data_t

If a subtest fails, cleanup_crtc() never gets called and then the
test_data_t structure for the test is lost, including the CRC file
descriptor that we never got a chance to release; this causes all
subsequent tests to fail with -EBUSY at igt_pipe_crc_new().

The split between permanent data_t and temporary test_data_t doesn't
seem to serve a purpose, so just combine the fields from both into
data_t.  This will prevent us from losing the CRC filedescriptor so that
we can properly close and reopen it after a failed test.

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>