6249695 setuname cmd calls kvm_nlist even if kvm_open fails

Summary:
All comments in bug apply.

Patch:
http://icculus.org/~eviltypeguy/6249695.patch

Lint/cstyle Patch (must be applied after original patch):
http://icculus.org/~eviltypeguy/6249695_lint.patch

Solution:
The solution was to bail out of further error checks that simply turn around and set rtncd = -1. The reason for this being that if kd is NULL, rtncd is set to -1, and there is little point in running other checks that will do the same thing.

Testing:
The new setuname binary still compiles successfully after applying the first or second patches. It was tested both before and after the lint patch using the options documented in the setuname manpage.