generic: fix static builds by removing unnecessary header include

Introduced in 74c5b43 .

While reworking buffer types, a header include got added to the top of
generic.c (likely automatically placed by an editor). This header does
not seem to be present in the alpine build environment, thus causing the
static builds to fail.

Since this header is not even needed, it can be removed.

Signed-off-by: Eric Richter <[email protected]>

generic.c

@@ -2,7 +2,6 @@
  * SPDX-License-Identifier: Apache-2.0
  * Copyright 2022-2023 IBM Corp.
  */
-#include <bits/stdint-uintn.h>
 #include <stdio.h>
 #include <string.h>
 #include <errno.h>