fs/affs: pr_debug cleanup

- Remove AFFS: prefix (defined in pr_fmt)

- Use __func__

- Separate format/arguments on lines > 80 characters.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>