[conformal/btcec] e3c2b8: Fix a comment typo.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/conformal/btcec
  Commit: e3c2b875361c957c0c73d9f0e5c645b6ea977213
      
https://github.com/conformal/btcec/commit/e3c2b875361c957c0c73d9f0e5c645b6ea977213
  Author: Dave Collins <da...@conformal.com>
  Date:   2013-12-26 (Thu, 26 Dec 2013)

  Changed paths:
    M btcec.go

  Log Message:
  -----------
  Fix a comment typo.