Typo.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@155679 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/ToolChains.cpp b/lib/Driver/ToolChains.cpp
index b56add3..68255f4 100644
--- a/lib/Driver/ToolChains.cpp
+++ b/lib/Driver/ToolChains.cpp
@@ -886,7 +886,7 @@
       DAL->AddJoinedArg(0, Opts.getOption(options::OPT_mtune_EQ), "core2");
 
   // Add the arch options based on the particular spelling of -arch, to match
-  // how the driver driver works.
+  // how the driver works.
   if (BoundArch) {
     StringRef Name = BoundArch;
     const Option *MCpu = Opts.getOption(options::OPT_mcpu_EQ);