Client: eliminate SetExpired(), call Close() directly

src/client/Write.cxx

@@ -21,13 +21,6 @@
 
 #include <string.h>
 
-bool
-Client::Write(const void *data, size_t length) noexcept
-{
-	/* if the client is going to be closed, do nothing */
-	return !IsExpired() && FullyBufferedSocket::Write(data, length);
-}
-
 bool
 Client::Write(const char *data) noexcept
 {