lg2: commit: avoid double quoting strings

The JSON `.dump()` function will quote a string, if that is what the
JSON type was.  This results in AdditionalData fields which appear
double-quoted.  Fix this by checking the type and using the raw value
for strings.

Before:
```
.AdditionalData                             property  as        8 "READING_VALUE=98.6" "SENSOR_NAME=\"Inlet Temperature\"" "THRESHOLD_VALUE=40.0" "UNITS=\"xyz.openbmc_project.Sensor.Value.Unit.DegreesC\"" "_CODE_FILE=../log_create_main.cpp" "_CODE_FUNC=int generate_event(const std::string&, const nlohmann::json_abi_v3_11_2::json&)" "_CODE_LINE=34" "_PID=1931265" emits-change writable
```

After:
```
.AdditionalData                             property  as        8 "READING_VALUE=98.6" "SENSOR_NAME=Inlet Temperature" "THRESHOLD_VALUE=40.0" "UNITS=xyz.openbmc_project.Sensor.Value.Unit.DegreesC" "_CODE_FILE=../log_create_main.cpp" "_CODE_FUNC=int generate_event(const std::string&, const nlohmann::json_abi_v3_11_2::json&)" "_CODE_LINE=34" "_PID=2219391" emits-change writable
```

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie29ab523f7517d5484a833d91c58c2058b710069
diff --git a/lib/lg2_commit.cpp b/lib/lg2_commit.cpp
index d5ae41b..2f1caab 100644
--- a/lib/lg2_commit.cpp
+++ b/lib/lg2_commit.cpp
@@ -93,7 +93,14 @@
             continue;
         }
 
-        result.emplace(item.key(), item.value().dump());
+        if (item.value().type() == nlohmann::json::value_t::string)
+        {
+            result.emplace(item.key(), item.value());
+        }
+        else
+        {
+            result.emplace(item.key(), item.value().dump());
+        }
     }
 
     return result;