clang-15: fixes for emplace

clang-tidy-15 is raising the following warning, which it automatically
fixed:

```
../include/sessions.hpp:262:38: error: unnecessary temporary object created while calling emplace [modernize-use-emplace,-warnings-as-errors]
        auto it = authTokens.emplace(std::make_pair(sessionToken, session));
                                     ^~~~~~~~~~~~~~~                     ~
```

Apply automatically generated fix.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I425efdcba4bf08b03d64f8fb913eab956f5a198d
diff --git a/include/sessions.hpp b/include/sessions.hpp
index 3dabff4..79b344a 100644
--- a/include/sessions.hpp
+++ b/include/sessions.hpp
@@ -259,7 +259,7 @@
             std::string(clientId), redfish::ip_util::toString(clientIp),
             std::chrono::steady_clock::now(), persistence, false,
             isConfigureSelfOnly});
-        auto it = authTokens.emplace(std::make_pair(sessionToken, session));
+        auto it = authTokens.emplace(sessionToken, session);
         // Only need to write to disk if session isn't about to be destroyed.
         needWrite = persistence == PersistenceType::TIMEOUT;
         return it.first->second;