selftests/mm: allow tests to run with no huge pages support

selftests/mm: allow tests to run with no huge pages support

Currently the mm selftests refuse to run if huge pages are not available
in the current system but this is an optional feature and not all the
tests actually require them.  Change the test during startup to be
non-fatal and skip or omit tests which actually rely on having huge pages,
allowing the other tests to be run.

The gup_test does support using madvise() to configure huge pages but it
ignores the error code so we just let it run.

Link: https://lkml.kernel.org/r/20250212-kselftest-mm-no-hugepages-v1-2-44702f538522@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Nico Pache <npache@redhat.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>