Fix a race condition that resulted in multiple calls to ServiceClient::call() on a non-persistent connection accidentally use the same ServiceServerLink which could cause deadlock (and likely a crash, though that hasn't been seen).
Fix a race condition that resulted in multiple calls to ServiceClient::call() on a non-persistent connection accidentally use the same ServiceServerLink which could cause deadlock (and likely a crash, though that hasn't been seen).

#2336



ros/ros,ros/ros,ros/ros