Remove unused argument.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@177303 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/WindowsToolChain.cpp b/lib/Driver/WindowsToolChain.cpp
index df4d72e..52d7e19 100644
--- a/lib/Driver/WindowsToolChain.cpp
+++ b/lib/Driver/WindowsToolChain.cpp
@@ -36,7 +36,7 @@
   : ToolChain(D, Triple, Args) {
 }
 
-Tool &Windows::SelectTool(const Compilation &C, const JobAction &JA) const {
+Tool &Windows::SelectTool(const JobAction &JA) const {
   Action::ActionClass Key;
   if (getDriver().ShouldUseClangCompiler(JA))
     Key = Action::AnalyzeJobClass;