[SCSI] st: Use mutex instead of semaphore

The 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>
Acked-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index a4f7b84..73c44cb 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -1485,7 +1485,7 @@
 	struct st_buffer *STbp;
 	char *name = tape_name(STp);
 
-	if (down_interruptible(&STp->lock))
+	if (mutex_lock_interruptible(&STp->lock))
 		return -ERESTARTSYS;
 
 	retval = rw_checks(STp, filp, count);
@@ -1736,7 +1736,7 @@
 	if (SRpnt != NULL)
 		st_release_request(SRpnt);
 	release_buffering(STp, 0);
-	up(&STp->lock);
+	mutex_unlock(&STp->lock);
 
 	return retval;
 }
@@ -1942,7 +1942,7 @@
 	struct st_buffer *STbp = STp->buffer;
 	DEB( char *name = tape_name(STp); )
 
-	if (down_interruptible(&STp->lock))
+	if (mutex_lock_interruptible(&STp->lock))
 		return -ERESTARTSYS;
 
 	retval = rw_checks(STp, filp, count);
@@ -2069,7 +2069,7 @@
 		release_buffering(STp, 1);
 		STbp->buffer_bytes = 0;
 	}
-	up(&STp->lock);
+	mutex_unlock(&STp->lock);
 
 	return retval;
 }
@@ -3226,7 +3226,7 @@
 	char *name = tape_name(STp);
 	void __user *p = (void __user *)arg;
 
-	if (down_interruptible(&STp->lock))
+	if (mutex_lock_interruptible(&STp->lock))
 		return -ERESTARTSYS;
 
         DEB(
@@ -3537,7 +3537,7 @@
 			retval = (-EFAULT);
 		goto out;
 	}
-	up(&STp->lock);
+	mutex_unlock(&STp->lock);
 	switch (cmd_in) {
 		case SCSI_IOCTL_GET_IDLUN:
 		case SCSI_IOCTL_GET_BUS_NUMBER:
@@ -3563,7 +3563,7 @@
 	return retval;
 
  out:
-	up(&STp->lock);
+	mutex_unlock(&STp->lock);
 	return retval;
 }
 
@@ -4029,7 +4029,7 @@
 
 	tpnt->density_changed = tpnt->compression_changed =
 	    tpnt->blksize_changed = 0;
-	init_MUTEX(&tpnt->lock);
+	mutex_init(&tpnt->lock);
 
 	st_nr_dev++;
 	write_unlock(&st_dev_arr_lock);