lib/test_vmalloc.c: restrict default test mask to avoid test warnings

lib/test_vmalloc.c: restrict default test mask to avoid test warnings

When the vmalloc test is built into the kernel, it runs automatically
during the boot.  The current-default "run_test_mask" includes all test
cases, including those which are designed to fail and which trigger kernel
warnings.

These kernel splats can be misinterpreted as actual kernel bugs, leading
to false alarms and unnecessary reports.

To address this, limit the default test mask to only the first few tests
which are expected to pass cleanly.  These tests are safe and should not
generate any warnings unless there is a real bug.

Users who wish to explicitly run specific test cases have to pass the
run_test_mask as a boot parameter or at module load time.

Link: https://lkml.kernel.org/r/20250623184035.581229-2-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: David Wang <00107082@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>