README.md: update MMA7660 snippet to reflect current reality

Signed-off-by: Jon Trulson <jtrulson@ics.com>

README.md

@@ -37,29 +37,21 @@ A sensor/actuator is expected to work as such (here is the MMA7660 accelerometer
   accel->setModeStandby();
 
   // enable 64 samples per second
-  accel->setSampleRate(upm::MMA7660::AUTOSLEEP_64);
-  
+  accel->setSampleRate(MMA7660_AUTOSLEEP_64);
+
   // place device into active mode
   accel->setModeActive();
 
   while (shouldRun)
     {
-      int x, y, z;
-      
-      accel->getRawValues(&x, &y, &z);
-      cout << "Raw values: x = " << x 
-           << " y = " << y
-           << " z = " << z
-           << endl;
-      
       float ax, ay, az;
-      
+
       accel->getAcceleration(&ax, &ay, &az);
-      cout << "Acceleration: x = " << ax 
+      cout << "Acceleration: x = " << ax
            << "g y = " << ay
            << "g z = " << az
            << "g" << endl;
-      
+
       usleep(500000);
     }
 ```