Fix copy in AES-KW.

The AES-KW code from 93a3dcd57262f5bbd84adaa5565abb14f95d79ae would
write 8 bytes past the end of the out buffer.

https://code.google.com/p/chromium/issues/detail?id=398699

Change-Id: I6e1a2884790f69cdbefb59ed60d71459b7327b89
1 file changed