[PATCH] Remove unused kernel config option ZISOFS_FS

Remove the kernel config option ZISOFS_FS, since it appears that the actual
option is simply ZISOFS.

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>