jbd: config_jbd_debug cannot create /proc entry

The jbd-debug file used to be located in /proc/sys/fs/jbd-debug, but
create_proc_entry() does not do lookups on file names that are more that
one directory deep.  This causes the entry creation to fail and hence, no
proc file is created.

Instead of fixing this on procfs might as well move the jbd2-debug file to
debugfs which would be the preferred location for this kind of tunable.
The new location is now /sys/kernel/debug/jbd/jbd-debug.

[akpm@linux-foundation.org: zillions of cleanups]
Signed-off-by: Jose R. Santos <jrs@us.ibm.com>
Acked-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/jbd.h b/include/linux/jbd.h
index d77f67d..16e7ed8 100644
--- a/include/linux/jbd.h
+++ b/include/linux/jbd.h
@@ -58,7 +58,7 @@
  * CONFIG_JBD_DEBUG is on.
  */
 #define JBD_EXPENSIVE_CHECKING
-extern int journal_enable_debug;
+extern u8 journal_enable_debug;
 
 #define jbd_debug(n, f, a...)						\
 	do {								\