Fix segfault is bool option is used on command line and fails parsing

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/init.c b/init.c
index 7246bd8..0cc6a52 100644
--- a/init.c
+++ b/init.c
@@ -1726,8 +1726,13 @@
 			}
 
 			ret = fio_cmd_option_parse(td, opt, val);
-			if (ret)
+			if (ret) {
+				if (td) {
+					put_job(td);
+					td = NULL;
+				}
 				do_exit++;
+			}
 
 			if (!ret && !strcmp(opt, "ioengine")) {
 				free_ioengine(td);