parse: for option with posval, dump allowed values on failure

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/parse.c b/parse.c
index dddcb8e..35410b2 100644
--- a/parse.c
+++ b/parse.c
@@ -479,7 +479,8 @@
 				}
 			}
 			if (ret) {
-				log_err("value %d not in allowed range\n",ull);
+				log_err("fio: value %llu not allowed:\n", ull);
+				show_option_values(o);
 				return 1;
 			}
 		}