Tests: Fix compile errors on Clang

Since Clang enables a couple of warnings that we don't have in GCC,
these were not caught before. Included fixes:

- Use correct printf format string for `size_t`
- Don't compare Nonnull(Ref|Own)Ptr` to nullptr
- Fix unsigned int& => unsigned long& conversion

1 files changed, 1 insertions, 1 deletions

diff --git a/Tests/Kernel/fuzz-syscalls.cpp b/Tests/Kernel/fuzz-syscalls.cpp
index e51a39824b..3b7a812c41 100644
--- a/Tests/Kernel/fuzz-syscalls.cpp
+++ b/Tests/Kernel/fuzz-syscalls.cpp
@@ -134,7 +134,7 @@ static void do_random_tests()
         0xffffffff,
     };
     dbgln("Doing a few random syscalls with:");
-    for (unsigned long& interesting_value : interesting_values) {
+    for (const auto& interesting_value : interesting_values) {
         dbgln("  {0} ({0:p})", interesting_value);
     }
     for (size_t i = 0; i < fuzz_syscall_count; ++i) {