remove __UNUSED

No need since we have C++17.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

src/rpc/exec_file.cc

@@ -19,7 +19,7 @@ namespace rpc {
 int
 ExecFile::execute(const char* file, char* const* argv, int flags) {
   // Write the execued command and its parameters to the log fd.
-  int __UNUSED result;
+  [[maybe_unused]] int result;
 
   if (m_log_fd != -1) {
     for (char* const* itr = argv; *itr != NULL; itr++) {
@@ -89,7 +89,7 @@ ExecFile::execute(const char* file, char* const* argv, int flags) {
     for (int i = 3, last = sysconf(_SC_OPEN_MAX); i != last; i++)
       ::close(i);
 
-    int result = execvp(file, argv);
+    result = execvp(file, argv);
 
     _exit(result);
   }

src/rpc/scgi_task.cc

@@ -165,7 +165,7 @@ SCgiTask::event_read() {
   torrent::this_thread::poll()->remove_read(this);
 
   if (m_parent->log_fd() >= 0) {
-    int __UNUSED result;
+    [[maybe_unused]] int result;
 
     // Clean up logging, this is just plain ugly...
     //    write(m_logFd, "\n---\n", sizeof("\n---\n"));
@@ -326,7 +326,7 @@ SCgiTask::receive_write(const char* buffer, uint32_t length) {
   std::memcpy(m_buffer + headerSize, buffer, length);
 
   if (m_parent->log_fd() >= 0) {
-    int result [[maybe_unused]];
+    [[maybe_unused]] int result;
     result = write(m_parent->log_fd(), m_buffer, m_buffer_size);
     result = write(m_parent->log_fd(), "\n---\n", sizeof("\n---\n"));
   }

src/rpc/xmlrpc.cc

@@ -14,10 +14,10 @@ namespace rpc {
 void XmlRpc::initialize() {}
 void XmlRpc::cleanup() {}
 
-void XmlRpc::insert_command(__UNUSED const char* name, __UNUSED const char* parm, __UNUSED const char* doc) {}
-void XmlRpc::set_dialect(__UNUSED int dialect) {}
+void XmlRpc::insert_command(const char*, const char*, const char*) {}
+void XmlRpc::set_dialect(int) {}
 
-bool XmlRpc::process(__UNUSED const char* inBuffer, __UNUSED uint32_t length, __UNUSED slot_write slotWrite) { return false; }
+bool XmlRpc::process(const char*, uint32_t, slot_write) { return false; }
 
 int64_t XmlRpc::size_limit() { return 0; }
 void    XmlRpc::set_size_limit(uint64_t size) {}