Convert munmap operation to JNI

app/src/main/cpp/fdutils.c

@@ -23,10 +23,3 @@ Java_com_hippo_Native_getFd(JNIEnv *env, jclass clazz, jobject fileDescriptor) {
 
     return fd;
 }
-
-JNIEXPORT void JNICALL
-Java_com_hippo_Native_unmapDirectByteBuffer(JNIEnv *env, jclass clazz, jobject buffer) {
-    void *addr = (*env)->GetDirectBufferAddress(env, buffer);
-    size_t size = (*env)->GetDirectBufferCapacity(env, buffer);
-    if (munmap(addr, size)) LOGE("munmap addr:%p, size%zu failed!", addr, size);
-}