iovec-util: Reduce transitive includes

src/cryptsetup/cryptsetup-keyfile.c

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include "alloc-util.h"
 #include "cryptsetup-keyfile.h"
 #include "fileio.h"
 #include "log.h"

src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-fido2.c

@@ -4,6 +4,7 @@
 #include <libcryptsetup.h>
 #include <string.h>
 
+#include "alloc-util.h"
 #include "cryptsetup-token.h"
 #include "cryptsetup-token-util.h"
 #include "hexdecoct.h"

src/cryptsetup/cryptsetup-tokens/cryptsetup-token-systemd-tpm2.c

@@ -3,6 +3,7 @@
 #include <errno.h>
 #include <libcryptsetup.h>
 
+#include "alloc-util.h"
 #include "cryptsetup-token.h"
 #include "cryptsetup-token-util.h"
 #include "hexdecoct.h"

src/cryptsetup/cryptsetup-tokens/luks2-fido2.c

@@ -2,6 +2,7 @@
 
 #include <libcryptsetup.h>
 
+#include "alloc-util.h"
 #include "cryptsetup-token-util.h"
 #include "hexdecoct.h"
 #include "json-util.h"