Change replication upgrade tests to return pass on success

As of commit 3044839456249f6f70b9642a60ad9be3dfb6056c tests that
return something other than the prescribed success atom 'pass' to
indicate success result in test failure. Change the
replication_upgrade and replication2_upgrade tests that return the
result of the a call to lists:foreach/2 to instead return 'pass' to
indicate success.