Add --warnings-fatal/-w option

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
diff --git a/README b/README
index 3a85a8b..2eec1a2 100644
--- a/README
+++ b/README
@@ -129,6 +129,7 @@
 			May be "always", "never" or "auto"
 	--section=name	Only run specified section in job file
 	--alloc-size=kb	Set smalloc pool to this size in kb (def 1024)
+	--warnings-fatal Fio parser warnings are fatal
 
 
 Any parameters following the options will be assumed to be job files,