Fix typo in duff_1i1o1 where the strides were not being adjusted.
Fix typo in duff_1i1o1 where the strides were not being adjusted.

Ignore-this: bdca644eafce23e9e203bbeb5a4c023a

darcs-hash:20100630014432-f546f-6945873bb221fec2949e8c3d3ce7eb2431688952.gz

nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf,nqv/mupdf