Fix wording in sun.security.ec

File this issue on behalf of longxu@mail.ustc.edu.cn (https://github.com/longxu0509)

1. ECOperations.java#154
// Get 64 extra bits and reduce in to the nonce
.. in to -> .. into

2. XECOperations.java#148
* The extra high-order bits are masked off, the highest valid bit it set, and the
the highest valid bit it set -> the highest valid bit is set

3. EdDSAKeyPairGenerator.java#28
//import java.security.*;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;