drop unnecessary check, because typeof(null) already is "object", excluded in the first guard

lib/bunyan.js

@@ -967,7 +967,7 @@ function mkLogEmitter(minLevel) {
                 } else {
                     msgArgs = Array.prototype.slice.call(args, 1);
                 }
-            } else if (typeof (args[0]) !== 'object' && args[0] !== null ||
+            } else if (typeof (args[0]) !== 'object' ||
                     Array.isArray(args[0])) {
                 // `log.<level>(msg, ...)`
                 fields = null;