staging/android/vsoc: Remove duplicate header

Remove linux/mutex.h which is included more than once
Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Acked-by: Souptick Joarder <jrdr.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/vsoc.c

@@ -29,7 +29,6 @@
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
 #include <linux/interrupt.h>
-#include <linux/mutex.h>
 #include <linux/cdev.h>
 #include <linux/file.h>
 #include "uapi/vsoc_shm.h"