9p/fsdev: remove obsolete references to virtio

Most of the 9p code is now virtio agnostic. This patch does a final cleanup:
- drop references to Virtio from the header comments
- fix includes

Also drop a couple of leading empty lines while here.

Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com>

fsdev/file-op-9p.h

 /*
- * Virtio 9p
+ * 9p
  *
  * Copyright IBM, Corp. 2010
  *

fsdev/qemu-fsdev-dummy.c

 /*
- * Virtio 9p
+ * 9p
  *
  * Copyright IBM, Corp. 2010
  *

fsdev/qemu-fsdev-opts.c

 /*
- * Virtio 9p
+ * 9p
  *
  * This work is licensed under the terms of the GNU GPL, version 2 or
  * later.  See the COPYING file in the top-level directory.

fsdev/qemu-fsdev.c

 /*
- * Virtio 9p
+ * 9p
  *
  * Copyright IBM, Corp. 2010
  *

fsdev/qemu-fsdev.h

 /*
- * Virtio 9p
+ * 9p
  *
  * Copyright IBM, Corp. 2010
  *

hw/9pfs/9p.h

@@ -5,8 +5,6 @@
 #include <utime.h>
 #include <sys/resource.h>
 #include <glib.h>
-#include "standard-headers/linux/virtio_9p.h"
-#include "hw/virtio/virtio.h"
 #include "fsdev/file-op-9p.h"
 #include "fsdev/9p-iov-marshal.h"
 #include "qemu/thread.h"

hw/9pfs/codir.c

-
 /*
- * Virtio 9p backend
+ * 9p backend
  *
  * Copyright IBM, Corp. 2011
  *

hw/9pfs/cofile.c

-
 /*
- * Virtio 9p backend
+ * 9p backend
  *
  * Copyright IBM, Corp. 2011
  *

hw/9pfs/cofs.c

-
 /*
- * Virtio 9p backend
+ * 9p backend
  *
  * Copyright IBM, Corp. 2011
  *

hw/9pfs/coth.c

@@ -16,7 +16,6 @@
 #include "qemu-common.h"
 #include "block/thread-pool.h"
 #include "qemu/coroutine.h"
-#include "qemu/main-loop.h"
 #include "coth.h"
 
 /* Called from QEMU I/O thread.  */

hw/9pfs/coth.h

@@ -17,7 +17,8 @@
 
 #include "qemu/thread.h"
 #include "qemu/coroutine.h"
-#include "virtio-9p.h"
+#include "qemu/main-loop.h"
+#include "9p.h"
 
 /*
  * we want to use bottom half because we want to make sure the below

hw/9pfs/coxattr.c

-
 /*
- * Virtio 9p backend
+ * 9p backend
  *
  * Copyright IBM, Corp. 2011
  *