ACPI: pfr_telemetry: Fix info leak in pfrt_log_ioctl()

The "data_info" struct is copied to the user.  It has a 4 byte struct
hole after the last struct member so we need to memset that to avoid
copying uninitialized stack data to the user.

Fixes: b0013e03 ("ACPI: Introduce Platform Firmware Runtime Telemetry driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>