[SCSI] osst: Use mutex instead of semaphore

The OnStream SCSI Tape driver uses a semaphore as mutex.  Use the mutex API
instead of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Reviewed-by: Satyam Sharma <satyam@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Willem Riede <wrlk@riede.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/osst.h b/drivers/scsi/osst.h
index 2cc7b5a..5aa2274 100644
--- a/drivers/scsi/osst.h
+++ b/drivers/scsi/osst.h
@@ -4,6 +4,7 @@
 
 #include <asm/byteorder.h>
 #include <linux/completion.h>
+#include <linux/mutex.h>
 
 /*	FIXME - rename and use the following two types or delete them!
  *              and the types really should go to st.h anyway...
@@ -532,7 +533,7 @@
   struct scsi_driver *driver;
   unsigned capacity;
   struct scsi_device *device;
-  struct semaphore lock;       /* for serialization */
+  struct mutex lock;           /* for serialization */
   struct completion wait;      /* for SCSI commands */
   struct osst_buffer * buffer;