Fix missing sign conversion in ignore_error_type()

Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/options.c b/options.c
index 9096a32..50af7b4 100644
--- a/options.c
+++ b/options.c
@@ -269,7 +269,7 @@
 		} else {
 			error[i] = atoi(fname);
 			if (error[i] < 0)
-				error[i] = error[i];
+				error[i] = -error[i];
 		}
 		if (!error[i]) {
 			log_err("Unknown error %s, please use number value \n",