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/fs/ext4/super.c b/fs/ext4/super.c
index 4c8d31c..83f9cd3 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1037,7 +1037,7 @@
 			if (option < 0)
 				return 0;
 			if (option == 0)
-				option = JBD_DEFAULT_MAX_COMMIT_AGE;
+				option = JBD2_DEFAULT_MAX_COMMIT_AGE;
 			sbi->s_commit_interval = HZ * option;
 			break;
 		case Opt_data_journal: