Fix comment.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173700 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Driver/Driver.cpp b/lib/Driver/Driver.cpp
index dda7099..c97b378 100644
--- a/lib/Driver/Driver.cpp
+++ b/lib/Driver/Driver.cpp
@@ -863,7 +863,7 @@
 
       // Add a 'dsymutil' step if necessary, when debug info is enabled and we
       // have a compile input. We need to run 'dsymutil' ourselves in such cases
-      // because the debug info will refer to a temporary object file which is
+      // because the debug info will refer to a temporary object file which
       // will be removed at the end of the compilation process.
       if (Act->getType() == types::TY_Image) {
         ActionList Inputs;