fix file specification in comments

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

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

fs/jbd2/checkpoint.c

@@ -1,5 +1,5 @@
 /*
- * linux/fs/checkpoint.c
+ * linux/fs/jbd2/checkpoint.c
  *
  * Written by Stephen C. Tweedie <sct@redhat.com>, 1999
  *