Wrong description about sgx_ecc256_open_context in Doc

Hi, I notice there exists a wrong description about the exit of `sgx_ecc256_open_context` function.
In 2.11 version, it says (Page 285):
> sgx_ecc256_open_context is utilized to allocate and initialize a 256-bit
GF(p) cryptographic system. The caller does not allocate memory for the ECC
state that this function returns. The state is specific to the implementation of
the cryptography library and thus the allocation is performed by the library
itself. If the ECC cryptographic function using this cryptographic system is completed
or any error occurs, **_sgx_sha256_close_context_** should be called
to free the state allocated by this algorithm.

where the **sgx_sha256_close_context** should be **sgx_ecc256_close_context**.

The same description also exists in previous verision.