Minor typo in Windows src\makefile.vc6

[rodwiddowson]

This may be in purpose in which case please close.

I note that in makefile.vc6 (and derivatives) the debug objects usually have 'd' appended to their names (nonblockd.obj rawstrd.obj &c), but slist_wc.obj doesn't. The net result is that if you type

nmake .... release

followed by

name .... debug

nmake whines

NMAKE : warning U4004: too many rules for target 'slist_wc.obj'

[bagder]

Thanks!