Kernel: Remove more unused members of IPv4Socket.

I thought I had included these in the previous commit, but it turns out
I hadn't, duh.

Kernel/Net/IPv4Socket.cpp

@@ -91,7 +91,6 @@ KResult IPv4Socket::bind(const sockaddr* address, socklen_t address_size)
 
 KResult IPv4Socket::connect(FileDescription& description, const sockaddr* address, socklen_t address_size, ShouldBlock should_block)
 {
-    ASSERT(!m_bound);
     if (address_size != sizeof(sockaddr_in))
         return KResult(-EINVAL);
     if (address->sa_family != AF_INET)
@@ -106,12 +105,10 @@ KResult IPv4Socket::connect(FileDescription& description, const sockaddr* addres
 
 void IPv4Socket::attach(FileDescription&)
 {
-    ++m_attached_fds;
 }
 
 void IPv4Socket::detach(FileDescription&)
 {
-    --m_attached_fds;
 }
 
 bool IPv4Socket::can_read(FileDescription& description) const

Kernel/Net/IPv4Socket.h

@@ -59,9 +59,6 @@ protected:
 private:
     virtual bool is_ipv4() const override { return true; }
 
-    bool m_bound { false };
-    int m_attached_fds { 0 };
-
     IPv4Address m_local_address;
     IPv4Address m_peer_address;