Error was:
```
../../src/crypto/tests/TestChipCryptoPAL.cpp:1573:38: note: Access of 'csr' at negative byte offset -2
 1573 |         csr[length - 2] = (uint8_t) (csr[length - 2] + 1);
      |                                      ^~~~~~~~~~~~~~~

WARNING TIDY ../../src/crypto/tests/TestChipCryptoPAL.cpp: 1 warning treated as error
WARNING Tidy ../../src/crypto/tests/TestChipCryptoPAL.cpp ended with code 1
```

Cause was that a EXPECT was used where ASSERT should be used, which leads to
an access in mbedTLS unit test version, that should not have run.