Fix shared_error race in validation kernels

[SRO-SA]

Fixes #1

Summary:

• Replaces non-atomic shared_error updates with atomicOr in validate_expand_MathAPI_new2.
• Replaces non-atomic shared_error updates with atomicOr in validate_expand.
• Keeps the existing validation logic unchanged while removing shared-memory read-modify-write races.

Testing:

• I could not run compute-sanitizer racecheck locally because my laptop does not have CUDA access.
• I reviewed the affected kernel updates manually.
• Please rerun the racecheck reproducer from the issue to confirm the shared-memory race is resolved.