Fix unlikely leak in sendto_kdc

If a TCP connection is killed after it allocates the buffer (so is no
longer in READING state), free the buffer during cleanup.

(cherry picked from commit 6895dc9)

ticket: 8444
version_fixed: 1.13.7

src/lib/krb5/os/sendto_kdc.c

@@ -1512,7 +1512,7 @@ k5_sendto(krb5_context context, const krb5_data *message,
             closesocket(state->fd);
             free_http_tls_data(context, state);
         }
-        if (state->state == READING && state->in.buf != udpbuf)
+        if (state->in.buf != udpbuf)
             free(state->in.buf);
         if (callback_info) {
             callback_info->pfn_cleanup(callback_info->data,