changelog: clarify CMake option

Author: jonasnick

CHANGELOG.md

@@ -20,7 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 #### Changed
  - The implementation of the point multiplication algorithm used for signing and public key generation was changed, resulting in improved performance for those operations.
-   - The related configure option `--ecmult-gen-precision` was replaced with `--ecmult-gen-kb` (`ECMULT_GEN_KB` for CMake).
+   - The related configure option `--ecmult-gen-precision` was replaced with `--ecmult-gen-kb` (`SECP256K1_ECMULT_GEN_KB` for CMake).
    - This changes the supported precomputed table sizes for these operations. The new supported sizes are 2 KiB, 22 KiB, or 86 KiB (while the old supported sizes were 32 KiB, 64 KiB, or 512 KiB).
 
 #### ABI Compatibility