[btcsuite/btcd] 555778: Don't ignore errs setting consts in btcec init.

[Dave Collins]

  Branch: refs/heads/master
  Home:   https://github.com/btcsuite/btcd
  Commit: 555778e9d5a82d5f3be3ade0a9ddfbd0c05f39c9
      
https://github.com/btcsuite/btcd/commit/555778e9d5a82d5f3be3ade0a9ddfbd0c05f39c9
  Author: Dave Collins <da...@conformal.com>
  Date:   2015-02-06 (Fri, 06 Feb 2015)

  Changed paths:
    M btcec/btcec.go

  Log Message:
  -----------
  Don't ignore errs setting consts in btcec init.

This commit converts the initialization of the constants to use a function
which panics on error instead of just ignoring the error.  This is
acceptable since they are hard-coded constants and should never fail.