test/timeout: Fix `-Werror=maybe-uninitialized`
test/timeout: Fix `-Werror=maybe-uninitialized`

Fix this:
```
  timeout.c: In function ‘test_multi_timeout’:
  timeout.c:590:20: warning: ‘user_data’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    590 |                 if (cqe->user_data != user_data) {
        |                    ^
  timeout.c:601:51: warning: ‘time’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    601 |                 if (exp < time / 2 || exp > (time * 3) / 2) {
        |                                             ~~~~~~^~~~
```

Fixes: 37136cb4423b27dac2fc663b6a0c513b6d7d7ad1 ("test/timeout: add multi timeout reqs test with different timeout")
Cc: zhangyi (F) <a7de8e005dcb5f2bfcc28b04068b2854b332bf37@huawei.com>
Signed-off-by: Ammar Faizi <0d988a99f192f3d558e868bf3333f67e1ba6e8d8@students.amikom.ac.id>
Link: f3ae74d5e6a68943e5ffc338976debaf6ec3e63b@gnuweeb.org
Signed-off-by: Jens Axboe <cd8c6775e60d6f67a6984377324e5290df3d5358@kernel.dk>

axboe/liburing,axboe/liburing,axboe/liburing