output as tangentImpulse when it's drawFrictionImpulses.

[ikpil]

if ( draw->drawFrictionImpulses )
{
    b2Vec2 tangent = b2RightPerp( normal );
    b2Vec2 p1 = point->point;
    b2Vec2 p2 = b2MulAdd( p1, k_impulseScale * point->tangentImpulse, tangent );
    draw->DrawSegment( p1, p2, frictionColor, draw->context );
    snprintf( buffer, B2_ARRAY_COUNT( buffer ), "%.2f", point->normalImpulse ); // <---- point->tangentImpulse
    draw->DrawString( p1, buffer, b2_colorWhite, draw->context );
}