avoid harmless pgpath uninitialised compiler message

[submitted to -mm with 15]

--- diff/drivers/md/dm-mpath.c	2005-07-08 20:48:54.000000000 +0100
+++ source/drivers/md/dm-mpath.c	2005-07-08 20:48:41.000000000 +0100
@@ -382,7 +382,7 @@
 {
 	struct multipath *m = (struct multipath *) data;
 	struct hw_handler *hwh = &m->hw_handler;
-	struct pgpath *pgpath;
+	struct pgpath *pgpath = NULL;
 	unsigned init_required = 0, must_queue = 1;
 	unsigned long flags;