Add support for redirection replay of blktrace traces to another device

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/fio.h b/fio.h
index ad47762..729604d 100644
--- a/fio.h
+++ b/fio.h
@@ -260,6 +260,7 @@
 	char *write_iolog_file;
 	char *bw_log_file;
 	char *lat_log_file;
+	char *replay_redirect;
 
 	/*
 	 * Pre-run and post-run shell