tests: fix match_diff usage
Fix argument order in match_diff invocations:
the first argument has to be actual output,
the second argument has to be expected output.
* tests/aio.test: Swap match_diff arguments.
* tests/clock_nanosleep.test: Likewise.
* tests/clock_xettime.test: Likewise.
* tests/file_handle.test: Likewise.
* tests/getdents.test: Likewise.
* tests/getdents64.test: Likewise.
* tests/getrandom.test: Likewise.
* tests/inet-cmsg.test: Likewise.
* tests/ioctl.test: Likewise.
* tests/membarrier.test: Likewise.
* tests/mlock2.test: Likewise.
* tests/nanosleep.test: Likewise.
* tests/pselect6.test: Likewise.
* tests/readdir.test: Likewise.
* tests/readlink.test: Likewise.
* tests/readlinkat.test: Likewise.
* tests/rt_sigqueueinfo.test: Likewise.
* tests/seccomp.test: Likewise.
* tests/select.test: Likewise.
* tests/sendfile.test: Likewise.
* tests/sendfile64.test: Likewise.
* tests/struct_flock.test: Likewise.
* tests/sysinfo.test: Likewise.
* tests/time.test: Likewise.
* tests/timer_create.test: Likewise.
* tests/timer_xettime.test: Likewise.
* tests/timerfd_xettime.test: Likewise.
* tests/times-fail.test: Likewise.
* tests/times.test: Likewise.
* tests/umovestr2.test: Likewise.
* tests/userfaultfd.test: Likewise.
* tests/utime.test: Likewise.
* tests/utimensat.test: Likewise.
* tests/xet_robust_list.test: Likewise.
* tests/xetitimer.test: Likewise.
* tests/xettimeofday.test: Likewise.
diff --git a/tests/userfaultfd.test b/tests/userfaultfd.test
index b9c8368..2fe46ef 100755
--- a/tests/userfaultfd.test
+++ b/tests/userfaultfd.test
@@ -7,7 +7,7 @@
run_prog > /dev/null
OUT="$LOG.out"
run_strace -a38 -euserfaultfd $args > "$OUT"
-match_diff "$OUT" "$LOG"
+match_diff "$LOG" "$OUT"
rm -f "$OUT"
exit 0