Fix bad start_delay type

Should be unsigned long long, causes a bus error on HP-UX.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.h b/fio.h
index fc64e3a..b869dd1 100644
--- a/fio.h
+++ b/fio.h
@@ -223,7 +223,7 @@
 	unsigned int fsync_blocks;
 	unsigned int fdatasync_blocks;
 	unsigned int barrier_blocks;
-	unsigned long start_delay;
+	unsigned long long start_delay;
 	unsigned long long timeout;
 	unsigned long long ramp_time;
 	unsigned int overwrite;