jbd2: JBD_XXX to JBD2_XXX naming cleanup

change JBD_XXX macros to JBD2_XXX in JBD2/Ext4

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/include/linux/poison.h b/include/linux/poison.h
index d93c300..a9c31be 100644
--- a/include/linux/poison.h
+++ b/include/linux/poison.h
@@ -36,7 +36,8 @@
  */
 
 /********** fs/jbd/journal.c **********/
-#define JBD_POISON_FREE	0x5b
+#define JBD_POISON_FREE		0x5b
+#define JBD2_POISON_FREE	0x5c
 
 /********** drivers/base/dmapool.c **********/
 #define	POOL_POISON_FREED	0xa7	/* !inuse */