Don't bind unless shared memory says it is free (#7520)

testing/node-driver/src/main/java/net/corda/testing/driver/SharedMemoryIncremental.java

@@ -76,8 +76,7 @@ public class SharedMemoryIncremental extends PortAllocation {
                 newValue = (oldValue + 1);
             }
             boolean reserveSuccess = UNSAFE.compareAndSwapLong(null, startingAddress, oldValue, newValue);
-            boolean portAvailable = isLocalPortAvailable(newValue);
-            loopSuccess = reserveSuccess && portAvailable;
+            loopSuccess = reserveSuccess && isLocalPortAvailable(newValue);
         } while (!loopSuccess);
 
         return (int) newValue;