ieee1394: nodemgr: convert nodemgr_serialize semaphore to mutex

Another trivial sem2mutex conversion.

Side note:  nodemgr_serialize's purpose, when introduced in linux1394's
revision 529 in July 2002, was to protect several data structures which
are now largely handled by or together with Linux' driver core and are
now protected by the LDM's own mechanisms.  It may very well be possible
to remove this mutex now.  But fully parallelized node scanning is on
our long-term TODO list anyway; the mutex will certainly go away then.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Index: linux/drivers/ieee1394/nodemgr.c
===================================================================
--- linux.orig/drivers/ieee1394/nodemgr.c	2006-07-02 12:23:05.000000000 +0200
+++ linux/drivers/ieee1394/nodemgr.c	2006-07-02 12:23:42.000000000 +0200
@@ -158,7 +158,7 @@ static struct csr1212_bus_ops nodemgr_cs
  * but now we are much simpler because of the LDM.
  */
 
-static DECLARE_MUTEX(nodemgr_serialize);
+static DEFINE_MUTEX(nodemgr_serialize);
 
 struct host_info {
 	struct hpsb_host *host;
@@ -1621,7 +1621,7 @@ static int nodemgr_host_thread(void *__h
 		if (kthread_should_stop())
 			goto exit;
 
-		if (down_interruptible(&nodemgr_serialize)) {
+		if (mutex_lock_interruptible(&nodemgr_serialize)) {
 			if (try_to_freeze())
 				continue;
 			goto exit;
@@ -1650,7 +1650,7 @@ static int nodemgr_host_thread(void *__h
 		if (!nodemgr_check_irm_capability(host, reset_cycles) ||
 		    !nodemgr_do_irm_duties(host, reset_cycles)) {
 			reset_cycles++;
-			up(&nodemgr_serialize);
+			mutex_unlock(&nodemgr_serialize);
 			continue;
 		}
 		reset_cycles = 0;
@@ -1668,10 +1668,10 @@ static int nodemgr_host_thread(void *__h
 		/* Update some of our sysfs symlinks */
 		nodemgr_update_host_dev_links(host);
 
-		up(&nodemgr_serialize);
+		mutex_unlock(&nodemgr_serialize);
 	}
 unlock_exit:
-	up(&nodemgr_serialize);
+	mutex_unlock(&nodemgr_serialize);
 exit:
 	HPSB_VERBOSE("NodeMgr: Exiting thread");
 	return 0;