[JFFS2] Debug code clean up - step 2

If debugging is disabled, define debugging functions as empty macros, instead
of using Dx() explicitly.

Signed-off-by: Artem B. Bityutskiy <dedekind@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --cc fs/jffs2/build.c
Simple merge

diff --cc fs/jffs2/fs.c
Simple merge

diff --cc fs/jffs2/gc.c
Simple merge

diff --cc fs/jffs2/readinode.c
Simple merge

diff --cc fs/jffs2/wbuf.c
Simple merge