PR #13056: Use `operator->` with XLA FFI Result Buffers in custom call docs
PR #13056: Use `operator->` with XLA FFI Result Buffers in custom call docs

Imported from GitHub PR https://github.com/openxla/xla/pull/13056


Copybara import of the project:

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7940a1a02a0f93736a88406958edf62488bdbe19 by Andrey Portnoy <aportnoy@nvidia.com>:

Use `operator->` with XLA FFI Result Buffers in custom call docs

Merging this change closes #13056

FUTURE_COPYBARA_INTEGRATE_REVIEW=https://github.com/openxla/xla/pull/13056 from openxla:aportnoy/ffi-docs-fix-result-syntax 7940a1a02a0f93736a88406958edf62488bdbe19
