Remove the unused class loader. (#2612)

apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/plugin/PluginFinder.java

@@ -67,8 +67,7 @@ public class PluginFinder {
         }
     }
 
-    public List<AbstractClassEnhancePluginDefine> find(TypeDescription typeDescription,
-        ClassLoader classLoader) {
+    public List<AbstractClassEnhancePluginDefine> find(TypeDescription typeDescription) {
         List<AbstractClassEnhancePluginDefine> matchedPlugins = new LinkedList<AbstractClassEnhancePluginDefine>();
         String typeName = typeDescription.getTypeName();
         if (nameMatchDefine.containsKey(typeName)) {

apm-sniffer/apm-agent/src/main/java/org/apache/skywalking/apm/agent/SkyWalkingAgent.java

@@ -116,7 +116,7 @@ public class SkyWalkingAgent {
         @Override
         public DynamicType.Builder<?> transform(DynamicType.Builder<?> builder, TypeDescription typeDescription,
             ClassLoader classLoader, JavaModule module) {
-            List<AbstractClassEnhancePluginDefine> pluginDefines = pluginFinder.find(typeDescription, classLoader);
+            List<AbstractClassEnhancePluginDefine> pluginDefines = pluginFinder.find(typeDescription);
             if (pluginDefines.size() > 0) {
                 DynamicType.Builder<?> newBuilder = builder;
                 EnhanceContext context = new EnhanceContext();