cxl/mem: Fix for the index of Clear Event Record Handle

The dev_dbg info for Clear Event Records mailbox command would report
the handle of the next record to clear not the current one.

This was because the index 'i' had incremented before printing the
current handle value.

Fixes: 6ebe28f9 ("cxl/mem: Read, trace, and clear events on driver load")
Signed-off-by: Yuquan Wang <wangyuquan1236@phytium.com.cn>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Fan Ni <fan.ni@samsung.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>