iovec-util: Reduce transitive includes

src/bootctl/bootctl-install.c

@@ -1,5 +1,6 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
+#include "alloc-util.h"
 #include "bootctl.h"
 #include "bootctl-install.h"
 #include "bootctl-random-seed.h"

src/bootctl/bootctl-set-efivar.c

@@ -3,6 +3,7 @@
 #include <uchar.h>
 #include <unistd.h>
 
+#include "alloc-util.h"
 #include "bootctl.h"
 #include "bootctl-set-efivar.h"
 #include "efi-loader.h"

src/bootctl/bootctl-status.c

@@ -4,6 +4,7 @@
 #include <sys/mman.h>
 #include <unistd.h>
 
+#include "alloc-util.h"
 #include "bootctl.h"
 #include "bootctl-status.h"
 #include "bootctl-util.h"

src/bootctl/bootctl-util.c

@@ -2,6 +2,7 @@
 
 #include <sys/mman.h>
 
+#include "alloc-util.h"
 #include "bootctl.h"
 #include "bootctl-util.h"
 #include "errno-util.h"