revert fib improvement

Author: davecheney

2-benchmarking/examples/fib/fib_test.go

@@ -10,8 +10,6 @@ func Fib(n int) int {
 		return 0
 	case 1:
 		return 1
-	case 2:
-		return 1
 	default:
 		return Fib(n-1) + Fib(n-2)
 	}