llvm-config: Show OBJROOT rather than OBJROOT/BUILD_MODE in MakefileStyle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197818 91177308-0d34-0410-b5e6-96231b3b80d8

tools/llvm-config/llvm-config.cpp

@@ -240,6 +240,7 @@ int main(int argc, char **argv) {
     // layout.
     switch (DevelopmentTreeLayout) {
     case MakefileStyle:
+      ActivePrefix = ActiveObjRoot;
       ActiveBinDir = ActiveObjRoot + "/" + build_mode + "/bin";
       ActiveLibDir = ActiveObjRoot + "/" + build_mode + "/lib";
       break;