Readd EVP_CIPHER_CTX_set_key_length.

This only applies to RC4, but it is still used by some Android code.

Change-Id: I4cf86269ffb7a230576da1bb2bfef7e1d4f234d6
Reviewed-on: https://boringssl-review.googlesource.com/1621
Reviewed-by: Adam Langley <agl@google.com>
3 files changed