Kernel: Fix bogus error codes from raw socket protocol_{send,receive}

Since these return KResultOr, we should not negate the error code.

Kernel/Net/IPv4Socket.h

@@ -74,8 +74,8 @@ protected:
 
     virtual KResult protocol_bind() { return KSuccess; }
     virtual KResult protocol_listen() { return KSuccess; }
-    virtual KResultOr<size_t> protocol_receive(ReadonlyBytes /* raw_ipv4_packet */, UserOrKernelBuffer&, size_t, int) { return -ENOTIMPL; }
-    virtual KResultOr<size_t> protocol_send(const UserOrKernelBuffer&, size_t) { return -ENOTIMPL; }
+    virtual KResultOr<size_t> protocol_receive(ReadonlyBytes /* raw_ipv4_packet */, UserOrKernelBuffer&, size_t, int) { return ENOTIMPL; }
+    virtual KResultOr<size_t> protocol_send(const UserOrKernelBuffer&, size_t) { return ENOTIMPL; }
     virtual KResult protocol_connect(FileDescription&, ShouldBlock) { return KSuccess; }
     virtual KResultOr<u16> protocol_allocate_local_port() { return ENOPROTOOPT; }
     virtual bool protocol_is_disconnected() const { return false; }