[IRDA]: use mutex instead of semaphore in VLSI 82C147 IrDA controller driver

The VLSI 82C147 IrDA controller driver uses a semaphore as mutex.  Use the
mutex API instead of the (binary) semaphore.

Signed-off-by: Matthias Kaehlcke <matthias.kaehlcke@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/irda/vlsi_ir.h b/drivers/net/irda/vlsi_ir.h
index 2d3b773..ca12a60 100644
--- a/drivers/net/irda/vlsi_ir.h
+++ b/drivers/net/irda/vlsi_ir.h
@@ -728,7 +728,7 @@
 	struct timeval		last_rx;
 
 	spinlock_t		lock;
-	struct semaphore	sem;
+	struct mutex		mtx;
 
 	u8			resume_ok;	
 	struct proc_dir_entry	*proc_entry;