Fix warnings for unused results
Fix warnings for unused results

This removes three warnings from the build and it's probably not bad to
check the result there, to see if the operation succeeded.

The warnings were:

  Result of call to update(input:) is unused.

opfeffer/swift-sodium,ziogaschr/swift-sodium,jedisct1/swift-sodium,blochberger/swift-sodium,ziogaschr/swift-sodium,blochberger/swift-sodium,jedisct1/swift-sodium,ziogaschr/swift-sodium,opfeffer/swift-sodium,opfeffer/swift-sodium,blochberger/swift-sodium,opfeffer/swift-sodium,ziogaschr/swift-sodium,blochberger/swift-sodium,jedisct1/swift-sodium