[pass] generate shouldn't show password by default

[Jason A. Donenfeld]

What is your attack model exactly? Shared GPU buffers that the driver
doesn't clear as a performance optimization, so you worry about other
sandboxed processes who have access to GPU (like Chrome) learning the
password? Or is it just an issue of the person looking over your
shoulder being able to memorize randomly generated 17 character&symbol
passwords really fast?