remove useless code.

arthas-vmtool/src/main/java/arthas/VmTool.java

@@ -70,11 +70,6 @@ public class VmTool implements VmToolMXBean {
      */
     private static synchronized native Class<?>[] getAllLoadedClasses0(Class<?> klass);
 
-    @Override
-    public String check() {
-        return check0();
-    }
-
     @Override
     public void forceGc() {
         forceGc0();

arthas-vmtool/src/main/java/arthas/VmToolMXBean.java

@@ -14,10 +14,6 @@ package arthas;
  * @author hengyunabc 2021-04-26
  */
 public interface VmToolMXBean {
-    /**
-     * 检测jni-lib是否正常，如果正常，应该输出OK
-     */
-    public String check();
 
     /**
      * https://docs.oracle.com/javase/8/docs/platform/jvmti/jvmti.html#ForceGarbageCollection

arthas-vmtool/src/main/native/src/jni-library.cpp

@@ -51,12 +51,6 @@ Java_arthas_VmTool_forceGc0(JNIEnv *env, jclass thisClass) {
     jvmti->ForceGarbageCollection();
 }
 
-extern "C"
-JNIEXPORT jstring JNICALL
-Java_arthas_VmTool_check0(JNIEnv *env, jclass thisClass) {
-    return env->NewStringUTF("OK");
-}
-
 extern "C"
 jlong getTag() {
     return ++tagCounter;