stat: report zone reset count in json output format

When --output-format=json option is specified, fio currently does not
report the zone reset count even when zbd zonemode is specified. To
report it, add the new item "zone_resets" to the json output format.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/stat.c b/stat.c
index 76b74b3..a67d355 100644
--- a/stat.c
+++ b/stat.c
@@ -1946,6 +1946,10 @@
 		json_object_add_value_array(data, "bw", bw);
 	}
 
+	if (ts->count_zone_resets)
+		json_object_add_value_int(root, "zone_resets",
+					  ts->nr_zone_resets);
+
 	return root;
 }