mei: fix device stall after wd is stopped

After watchdog was disabled the driver would stall
due to wrong calculation of credits reduction

The cat&paste bug was introduced in the commit
7bdf72d3
mei: introduce mei_data2slots wrapper
Signed-off-by: NTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mei/interrupt.c

@@ -1253,7 +1253,7 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 			if (dev->wd_timeout)
 				*slots -= mei_data2slots(MEI_START_WD_DATA_SIZE);
 			else
-				*slots -= mei_data2slots(MEI_START_WD_DATA_SIZE);
+				*slots -= mei_data2slots(MEI_WD_PARAMS_SIZE);
 		}
 	}
 	if (dev->stop)