Ensure that buffer contents are random across jobs as well

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/init.c b/init.c
index a920c6e..ed34269 100644
--- a/init.c
+++ b/init.c
@@ -515,6 +515,8 @@
 		td_fill_rand_seeds_os(td);
 	else
 		td_fill_rand_seeds_internal(td);
+
+	init_rand_seed(&td->buf_state, td->rand_seeds[7]);
 }
 
 /*