[tap] fix unit test
The new versions of rust panic when trying to open fd -1. This is a
workaround for the issue. It's only used in unit tests.
@@ -245,7 +245,7 @@ pub mod tests {
tap.set_offload(0).unwrap();
let faulty_tap = Tap {
- tap_file: unsafe { File::from_raw_fd(-1) },
+ tap_file: unsafe { File::from_raw_fd(-2) },
if_name: [0x01; 16],
};
assert!(faulty_tap.set_vnet_hdr_size(16).is_err());
