oslib-posix: Fix build on FreeBSD

Commit 10f5bff622 (util: Split out
exec_dir from os_find_datadir) moved code from os-posix.c to
util/oslib-posix.c but forgot to move a FreeBSD #include alongside,
needed for CTL_KERN among others.

Cc: Fam Zheng <famz@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <andreas.faerber@web.de>
Message-id: 1394717279-23406-1-git-send-email-andreas.faerber@web.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

os-posix.c

@@ -44,10 +44,6 @@
 #include <sys/prctl.h>
 #endif
 
-#ifdef __FreeBSD__
-#include <sys/sysctl.h>
-#endif
-
 static struct passwd *user_pwd;
 static const char *chroot_dir;
 static int daemonize;

util/oslib-posix.c

@@ -63,6 +63,10 @@ extern int daemon(int, int);
 #include <sys/syscall.h>
 #endif
 
+#ifdef __FreeBSD__
+#include <sys/sysctl.h>
+#endif
+
 int qemu_get_thread_id(void)
 {
 #if defined(__linux__)