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
7bdf72d3d8059a50214069ea4b87c2174645f40f
mei: introduce mei_data2slots wrapper

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index c6ffbbe..d78c05e 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -1253,7 +1253,7 @@
 			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)