tests: Avoid deprecated Name::set method

Change-Id: I53b92fdac0ae5ca7949cc6b6446eeb0cc9d6bc1b
Refs: #2505
diff --git a/tests/identity-fixture.cpp b/tests/identity-fixture.cpp
index 5032cf2..36ab807 100644
--- a/tests/identity-fixture.cpp
+++ b/tests/identity-fixture.cpp
@@ -63,7 +63,7 @@
       m_hasOldDefaultIdentity = false;
     }
 
-    m_newIdentity.set("/nlsr-test-identity");
+    m_newIdentity = "/nlsr-test-identity";
     m_newIdentity.appendVersion();
 
     // create the new identity and self-signed certificate
@@ -96,4 +96,4 @@
 
 BOOST_GLOBAL_FIXTURE(IdentityFixture)
 
-} // namespace nlsr
\ No newline at end of file
+} // namespace nlsr