OAuth Facebook login working but asking for password in registration page.

I am redirecting properly on facebook and google after click on login with fb or google but while redirecting its is showing me registration form with username of facebook or google and blank password field.

If i adding a password through redirected registration form and if will do again login through facebook or google next time it going to logged in automatically.

I don;t want to display registration form after user login with facebook or google.