migration: Clean up includes

Clean up includes so that osdep.h is included first and headers
which it implies are not included manually.

This commit was created with scripts/clean-includes.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1453832250-766-2-git-send-email-peter.maydell@linaro.org
diff --git a/migration/vmstate.c b/migration/vmstate.c
index a7ad7f2..bf3d5db 100644
--- a/migration/vmstate.c
+++ b/migration/vmstate.c
@@ -1,3 +1,4 @@
+#include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "migration/migration.h"
 #include "migration/qemu-file.h"