clang-cl /fallback: turn the note into a warning

llvm-svn: 201626
diff --git a/clang/lib/Driver/Job.cpp b/clang/lib/Driver/Job.cpp
index 7fd43e3..2775d89 100644
--- a/clang/lib/Driver/Job.cpp
+++ b/clang/lib/Driver/Job.cpp
@@ -164,8 +164,7 @@
     *ExecutionFailed = false;
 
   const Driver &D = getCreator().getToolChain().getDriver();
-  D.Diag(diag::note_drv_invoking_fallback).setForceEmit()
-      << Fallback->getExecutable();
+  D.Diag(diag::warn_drv_invoking_fallback) << Fallback->getExecutable();
 
   int SecondaryStatus = Fallback->Execute(Redirects, ErrMsg, ExecutionFailed);
   return SecondaryStatus;