update DynamoDBEntryConversion.TryFromEntry to make it more readable

Author: muhammad-othman

sdk/src/Services/DynamoDBv2/Custom/Conversion/DynamoDBEntryConversion.cs

@@ -571,14 +571,17 @@ public bool TryFromEntry(DynamoDBEntry entry, Type targetType, out object value)
 
             var d = entry as Document;
             if (d != null && TryFrom(d, targetType, out value))
-                return true;
-
-            value = null;
-
-            var n = entry as DynamoDBNull;
+                return true;
+
+            var n = entry as DynamoDBNull;
             if (n != null)
-                return true;
-
+            {
+                value = null;
+                return true;
+            }
+
+            // Could not convert entry to a known type, setting value to null as it's an out parameter
+            value = null;
             return false;
         }