Move several *_SUPER_MAGIC symbols to include/linux/magic.h.

Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/usbdevice_fs.h b/include/linux/usbdevice_fs.h
index 7b7aadb..617d8a1 100644
--- a/include/linux/usbdevice_fs.h
+++ b/include/linux/usbdevice_fs.h
@@ -32,11 +32,10 @@
 #define _LINUX_USBDEVICE_FS_H
 
 #include <linux/types.h>
+#include <linux/magic.h>
 
 /* --------------------------------------------------------------------- */
 
-#define USBDEVICE_SUPER_MAGIC 0x9fa2
-
 /* usbdevfs ioctl codes */
 
 struct usbdevfs_ctrltransfer {