fix versioned lib lookup with normalized full paths

this is admittedly a rather improbable use case, so unlikely to have any
real world effect.

Change-Id: If98f0de90043525f0555f8ddf98f8b4352e5a0a7
Reviewed-by: Joerg Bornemann <joerg.bornemann@theqtcompany.com>

qmake/generators/win32/winmakefile.cpp

@@ -156,7 +156,7 @@ Win32MakefileGenerator::findLibraries()
             (*it) = out;
         } else if(!exists(Option::fixPathToLocalOS(opt))) {
             QList<QMakeLocalFileName> lib_dirs;
-            QString file = opt;
+            QString file = Option::fixPathToTargetOS(opt);
             int slsh = file.lastIndexOf(Option::dir_sep);
             if(slsh != -1) {
                 lib_dirs.append(QMakeLocalFileName(file.left(slsh+1)));