Don't rely on operator << for object logging

In the upcoming fmt patch, we remove the use of streams, and a number of
our logging statements are relying on them.  This commit changes them to
no longer rely on operator>> or operator+ to build their strings.  This
alone isn't very useful, but in the context of the next patch makes the
automation able to do a complete conversion of all log statements
automatically.

Tested: enabled logging on local and saw log statements print to console

Signed-off-by: Ed Tanous <edtanous@google.com>
Change-Id: I0e5dc2cf015c6924037e38d547535eda8175a6a1
diff --git a/redfish-core/lib/managers.hpp b/redfish-core/lib/managers.hpp
index acaa40a..b0e2507 100644
--- a/redfish-core/lib/managers.hpp
+++ b/redfish-core/lib/managers.hpp
@@ -1872,8 +1872,8 @@
                 return;
             }
 
-            BMCWEB_LOG_DEBUG
-                << "Setting firmware version " + firmwareId + " to priority 0.";
+            BMCWEB_LOG_DEBUG << "Setting firmware version " << firmwareId
+                             << " to priority 0.";
 
             // Only support Immediate
             // An addition could be a Redfish Setting like