Fix broken dlltool --kill-at

[Aaron W. LaFramboise]

I'd like to point out that I beleive that Carlo Wood's patch (that
caused the breakage that this patch fixes) is incorrect, and that it
causes dlltool to interpret the internal name in a manner it should not.
 I've asserted that dlltool was correct before this patch in not using
the internal name when creating import libraries, and this is consistant
with the behavior of Microsoft LINK and LIB.

We are discussing the issue in this thread
<http://sourceforge.net/mailarchive/forum.php?thread_id=5516199&forum_id=5119>
and I hope we will come to a resolution soon.

Aaron W. LaFramboise