fix: style-compiler source maps & use vue-component-compiler instead of vue-loader in logs

Author: znck

src/assemble.js

@@ -177,7 +177,7 @@ module.exports = function assemble (source, filename, config) {
       output +=
         'if (Component.options.functional) {\n' +
         '  console.error("' +
-          '[vue-loader] ' + filename + ': functional components are not ' +
+          '[vue-component-compiler] ' + filename + ': functional components are not ' +
           'supported with templates, they should use render functions.' +
         '")\n}\n'
     }

src/style-compiler/index.js

@@ -12,7 +12,7 @@ function compileStyle (style, filename, config) {
   }, config.options)
 
   // source map
-  if (config.needMap && !style.map) {
+  if (config.needMap) {
     if (!style.map) {
       throw Error('Previous source map is missing.')
     }