maint: Reorder include directives for qemu-{nbd, io}

HACKING recommends listing system includes right after osdep.h,
and before any other in-project headers.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170721135047.25005-3-eblake@redhat.com>
diff --git a/qemu-nbd.c b/qemu-nbd.c
index 1086934..b8666bb 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -17,6 +17,10 @@
  */
 
 #include "qemu/osdep.h"
+#include <getopt.h>
+#include <libgen.h>
+#include <pthread.h>
+
 #include "qapi/error.h"
 #include "qemu-common.h"
 #include "qemu/cutils.h"
@@ -38,10 +42,6 @@
 #include "trace/control.h"
 #include "qemu-version.h"
 
-#include <getopt.h>
-#include <libgen.h>
-#include <pthread.h>
-
 #define SOCKET_PATH                "/var/lock/qemu-nbd-%s"
 #define QEMU_NBD_OPT_CACHE         256
 #define QEMU_NBD_OPT_AIO           257