Fix MustKillCouchbaseService for Openshift

TestRecoveryAfterOneNsServerFailureBucketOneReplica
TestNodeServiceDownRecovery

Both these tests fail in MustKillCouchbaseService:

=== RUN TestOperator/TestRecoveryAfterOneNsServerFailureBucketOneReplica
— FAIL: TestOperator/TestRecoveryAfterOneNsServerFailureBucketOneReplica (91.58s)
crd_util.go:26: creating couchbase cluster: test-couchbase-9hjjp
exec_util.go:139: Command: mv /etc/service/couchbase-server /tmp/
exec_util.go:140: stdout:
exec_util.go:141: stderr:
util.go:1304: command terminated with exit code 1
util.go:1305: goroutine 635 [running]:
runtime/debug.Stack(0xc0006e8b00, 0xc000a27b68, 0x1)
/usr/local/go/src/runtime/debug/stack.go:24 +0x9d
github.com/couchbase/couchbase-operator/test/e2e/e2eutil.Die(0xc0006e8b00, 0x257b6c0, 0xc000706480)
/Users/arunkumarsenthilnathan/go/src/github.com/couchbase/couchbase-operator/test/e2e/e2eutil/util.go:1305 +0x77
github.com/couchbase/couchbase-operator/test/e2e/e2eutil.MustExecShellInPod(0xc0006e8b00, 0xc000409780, 0xc000414600, 0x7, 0xc001094ae0, 0x19, 0x234e788, 0x26, 0xc00070e480, 0x45d964b800, ...)
/Users/arunkumarsenthilnathan/go/src/github.com/couchbase/couchbase-operator/test/e2e/e2eutil/exec_util.go:142 +0x327
github.com/couchbase/couchbase-operator/test/e2e/e2eutil.MustKillCouchbaseService(0xc0006e8b00, 0xc000409780, 0xc000414600, 0x7, 0xc001094ae0, 0x19, 0xc000414700, 0xa)
/Users/arunkumarsenthilnathan/go/src/github.com/couchbase/couchbase-operator/test/e2e/e2eutil/util.go:1313 +0x13e
github.com/couchbase/couchbase-operator/test/e2e.TestRecoveryAfterOneNsServerFailureBucketOneReplica(0xc0006e8b00)
/Users/arunkumarsenthilnathan/go/src/github.com/couchbase/couchbase-operator/test/e2e/node_test.go:624 +0x392
github.com/couchbase/couchbase-operator/test/e2e/framework.RecoverDecorator.func1(0xc0006e8b00)
/Users/arunkumarsenthilnathan/go/src/github.com/couchbase/couchbase-operator/test/e2e/framework/test_util.go:347 +0x69
testing.tRunner(0xc0006e8b00, 0xc00072b420)
/usr/local/go/src/testing/testing.go:909 +0xc9
created by testing.(*T).Run
/usr/local/go/src/testing/testing.go:960 +0x350