busybox

cp: fix option handling in non-longopt config

the patch getopt32: remove opt_complementary 22542eca18e5807b72ddc78999f5101e33f17a53

introduced a regressed in the cp command since it removed all aliases of arguments
if long_opts is not configured.

Patch by Sebastian Gottschall <s.gottschall@dd-wrt.com>

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>