Kernel: Use Userspace<T> for the bind syscall, and implementation

Author: https://github.com/bgianfo
Commit: 02660b5d60
Pull-request: https://github.com/SerenityOS/serenity/pull/3062
Reviewed-by: https://github.com/awesomekling

Kernel/Net/LocalSocket.cpp

@@ -91,7 +91,7 @@ void LocalSocket::get_peer_address(sockaddr* address, socklen_t* address_size)
     get_local_address(address, address_size);
 }
 
-KResult LocalSocket::bind(const sockaddr* user_address, socklen_t address_size)
+KResult LocalSocket::bind(Userspace<const sockaddr*> user_address, socklen_t address_size)
 {
     ASSERT(setup_state() == SetupState::Unstarted);
     if (address_size != sizeof(sockaddr_un))