The CXL spec (3.0, section 8.2.9.8.4) Lists Inject Poison and Clear
Poison as having the effects of "Immediate Data Change". Fix this in the
mock driver so that the command effect log is populated correctly.

Fixes: 371c1610 ("tools/testing/cxl: Mock the Inject Poison mailbox command")
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/20230602-vv-fw_update-v4-2-c6265bd7343b@intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>