missing_securebits: remove unnecessary header

Our kernel baseline is 5.4, hence all entries in the headers are defined
in linux/securebits.h.

src/basic/missing_securebits.h

@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: LGPL-2.1-or-later */
-#pragma once
-
-#include <linux/securebits.h>
-
-/* 746bf6d64275be0c65b0631d8a72b16f1454cfa1 (4.3) */
-#ifndef SECURE_NO_CAP_AMBIENT_RAISE
-#define SECURE_NO_CAP_AMBIENT_RAISE        6
-#define SECURE_NO_CAP_AMBIENT_RAISE_LOCKED 7  /* make bit-6 immutable */
-#define SECBIT_NO_CAP_AMBIENT_RAISE        (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
-#define SECBIT_NO_CAP_AMBIENT_RAISE_LOCKED (issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE_LOCKED))
-
-#undef  SECURE_ALL_BITS
-#define SECURE_ALL_BITS (issecure_mask(SECURE_NOROOT) |                 \
-                         issecure_mask(SECURE_NO_SETUID_FIXUP) |        \
-                         issecure_mask(SECURE_KEEP_CAPS) |              \
-                         issecure_mask(SECURE_NO_CAP_AMBIENT_RAISE))
-#endif

src/core/exec-invoke.c

@@ -2,6 +2,7 @@
 
 #include <linux/prctl.h>
 #include <linux/sched.h>
+#include <linux/securebits.h>
 #include <sys/eventfd.h>
 #include <sys/ioctl.h>
 #include <sys/mount.h>
@@ -43,7 +44,6 @@
 #include "journal-send.h"
 #include "memfd-util.h"
 #include "missing_sched.h"
-#include "missing_securebits.h"
 #include "missing_syscall.h"
 #include "mkdir-label.h"
 #include "osc-context.h"

src/shared/securebits-util.h

@@ -3,7 +3,7 @@
 
 #include <stdbool.h>
 
-#include "missing_securebits.h"
+#include <linux/securebits.h>
 
 int secure_bits_to_string_alloc(int i, char **s);
 int secure_bits_from_string(const char *s);