Updating pattern matching on class members

In an awesome Scala school session with @jjmmcc, it came up that one of the pattern matching example isn't valid syntax.  This is what I get in 2.9.2:

```
Welcome to Scala version 2.9.2 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_45).
Type in expressions to have them evaluated.
Type :help for more information.

scala> case class Calculator(brand: String, model: String)
defined class Calculator

scala> :paste
// Entering paste mode (ctrl-D to finish)

def calcType(calc: Calculator) = calc match {
  case calc.brand == "hp" && calc.model == "20B" => "financial"
  case calc.brand == "hp" && calc.model == "48G" => "scientific"
  case calc.brand == "hp" && calc.model == "30B" => "business"
  case _ => "unknown"
}

// Exiting paste mode, now interpreting.

<console>:10: error: not found: value &&
         case calc.brand == "hp" && calc.model == "20B" => "financial"
                                 ^
<console>:11: error: not found: value &&
         case calc.brand == "hp" && calc.model == "48G" => "scientific"
                                 ^
<console>:12: error: not found: value &&
         case calc.brand == "hp" && calc.model == "30B" => "business"
                                 ^
scala> calc match {
     | case calc.brand == "hp" => "hhhhhhp"
     | case _ => "unknown"
     | }
<console>:8: error: not found: value calc
              calc match {
              ^
<console>:9: error: value == is not a case class constructor, nor does it have an unapply/unapplySeq method
              case calc.brand == "hp" => "hhhhhhp"
                              ^
```

So I updated the example.