fs/affs: convert printk to pr_foo()

-All printk(KERN_foo converted to pr_foo()

-Default printk converted to pr_warn()

-Add pr_fmt to affs.h

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>