vnext_read
return (vnext_read(arg, uiop, ioflag, cr, ct));
retval = vnext_read(vf, uiop, ioflag, cr, ct);
rc = vnext_read(arg, uiop, ioflag, cr, ct);
extern int vnext_read(femarg_t *vf, uio_t *uiop, int ioflag, cred_t *cr,