GH-720 - change to strcmp.
GH-720 - change to strcmp.

The prior code didn't provide constant time comparison and it wasn't
necessary anyway. Removed in favor of strcmp. Kept the wrapper function
to maintain api consistency.

Signed-off-by: Nick Campbell <e31591b49bf5c9127aafb098f2b9d466891b32f9@gmail.com>

kelektiv/node.bcrypt.js,kelektiv/node.bcrypt.js,ncb000gt/node.bcrypt.js,ncb000gt/node.bcrypt.js,kelektiv/node.bcrypt.js,kelektiv/node.bcrypt.js,ncb000gt/node.bcrypt.js,ncb000gt/node.bcrypt.js,kelektiv/node.bcrypt.js