Don't re-format raw string literal contents when formatting is disable

Not entirely sure this is the best place to put this check, but it fixes
the immediate issue.

llvm-svn: 327253
diff --git a/clang/lib/Format/ContinuationIndenter.cpp b/clang/lib/Format/ContinuationIndenter.cpp
index d53cf80..000f82a 100644
--- a/clang/lib/Format/ContinuationIndenter.cpp
+++ b/clang/lib/Format/ContinuationIndenter.cpp
@@ -1480,7 +1480,7 @@
   // Compute the raw string style to use in case this is a raw string literal
   // that can be reformatted.
   auto RawStringStyle = getRawStringStyle(Current, State);
-  if (RawStringStyle) {
+  if (RawStringStyle && !Current.Finalized) {
     Penalty = reformatRawStringLiteral(Current, State, *RawStringStyle, DryRun);
   } else if (Current.IsMultiline && Current.isNot(TT_BlockComment)) {
     // Don't break multi-line tokens other than block comments and raw string