cleanup: add defines for default pareto or zipf values

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fio.h b/fio.h
index 5e352c6..be2f23a 100644
--- a/fio.h
+++ b/fio.h
@@ -642,6 +642,9 @@
 	FIO_RAND_DIST_PARETO,
 };
 
+#define FIO_DEF_ZIPF		1.1
+#define FIO_DEF_PARETO		0.2
+
 enum {
 	FIO_RAND_GEN_TAUSWORTHE = 0,
 	FIO_RAND_GEN_LFSR,