[SCSI] megaraid_mbox: use mutex instead of semaphore

The Megaraid Mailbox 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: "Patro, Sumant" <Sumant.Patro@lsi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/megaraid/mega_common.h b/drivers/scsi/megaraid/mega_common.h
index 26e1e6c..fef9ac9 100644
--- a/drivers/scsi/megaraid/mega_common.h
+++ b/drivers/scsi/megaraid/mega_common.h
@@ -21,6 +21,7 @@
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/blkdev.h>