fix file specification in comments

Many files include the filename at the beginning, serveral used a wrong one.

Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index c0d4ce1..a0f3390 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1,5 +1,5 @@
 /*
- * mm/page-writeback.c.
+ * mm/page-writeback.c
  *
  * Copyright (C) 2002, Linus Torvalds.
  *