fix jffs2 ACLs on big-endian with 16bit mode_t

casting int * to mode_t * is not a good thing - on a *lot* of big-endian
architectures mode_t happens to be smaller than int and there it breaks
quite spectaculary...

Fucked-up-by: commit cfc8dc6f
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>