[tests] Remove CAddrMan.Clear() call from CAddrDB::Read()

`bool CAddrDB::Read(CAddrMan& addr, CDataStream& ssPeers)` is _only_
called from the tests, and the call to addr.Clear() only exists so that
a test that Clear() is called passes. Remove that test and the call.

Author: jnewbery

src/addrdb.cpp

@@ -244,12 +244,7 @@ bool CAddrDB::Read(CAddrMan& addr)
 
 bool CAddrDB::Read(CAddrMan& addr, CDataStream& ssPeers)
 {
-    bool ret = DeserializeDB(ssPeers, addr, false);
-    if (!ret) {
-        // Ensure addrman is left in a clean state
-        addr.Clear();
-    }
-    return ret;
+    return DeserializeDB(ssPeers, addr, false);
 }
 
 void DumpAnchors(const fs::path& anchors_db_path, const std::vector<CAddress>& anchors)

src/test/addrman_tests.cpp

@@ -1083,13 +1083,12 @@ BOOST_AUTO_TEST_CASE(caddrdb_read_corrupted)
     BOOST_CHECK(addrman1.size() == 1);
     BOOST_CHECK(exceptionThrown);
 
-    // Test that CAddrDB::Read leaves addrman in a clean state if de-serialization fails.
+    // Test that CAddrDB::Read fails if peers.dat is corrupt
     CDataStream ssPeers2 = AddrmanToStream(addrmanCorrupted);
 
     CAddrMan addrman2(/* deterministic */ false, /* consistency_check_ratio */ 100);
     BOOST_CHECK(addrman2.size() == 0);
     BOOST_CHECK(!CAddrDB::Read(addrman2, ssPeers2));
-    BOOST_CHECK(addrman2.size() == 0);
 }