unix.users: minor fixes in 'passwd' description
unix.users: minor fixes in 'passwd' description

erg/factor,mcandre/factor,mcandre/factor,erg/factor,mcandre/factor,erg/factor,erg/factor,erg/factor,mcandre/factor,mcandre/factor,erg/factor,mcandre/factor,erg/factor,mcandre/factor