[PATCH] fix %s in affs_fill_super()

%s is only valid if array is known to contain NUL or precision is given and
does not exceed the size of array.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>