Zero m->current_path if it has failed, so that we choose a new one
more quickly.
--- diff/drivers/md/dm-mpath.c	2004-02-09 11:27:24.000000000 +0000
+++ source/drivers/md/dm-mpath.c	2004-02-10 15:34:16.000000000 +0000
@@ -226,6 +226,10 @@
 			iterate_paths(m, clear_tested);
 			m->nr_tested_paths = 0;
 		}
+
+		if (path == m->current_path)
+			m->current_path = NULL;
+
 		spin_unlock(&m->lock);
 	}