Fix GettingStarted sample

The GettingStarted sample is apparently intended to send a number from the transmitter
to the receiver and echo that same number back again, but the code wasn't outputting
the echoed number properly. Now it doesn, and the user can see that the same number was
sent and echoed back.

examples/GettingStarted/GettingStarted.ino

@@ -56,8 +56,8 @@ if (role == 1)  {
     
     Serial.println(F("Now sending"));
 
-    unsigned long time = micros();                             // Take the time, and send it.  This will block until complete
-     if (!radio.write( &time, sizeof(unsigned long) )){
+    unsigned long start_time = micros();                             // Take the time, and send it.  This will block until complete
+     if (!radio.write( &start_time, sizeof(unsigned long) )){
        Serial.println(F("failed"));
      }
         
@@ -78,15 +78,15 @@ if (role == 1)  {
     }else{
         unsigned long got_time;                                 // Grab the response, compare, and send to debugging spew
         radio.read( &got_time, sizeof(unsigned long) );
-        unsigned long time = micros();
+        unsigned long end_time = micros();
         
         // Spew it
         Serial.print(F("Sent "));
-        Serial.print(time);
+        Serial.print(start_time);
         Serial.print(F(", Got response "));
         Serial.print(got_time);
         Serial.print(F(", Round-trip delay "));
-        Serial.print(time-got_time);
+        Serial.print(end_time-start_time);
         Serial.println(F(" microseconds"));
     }