Fix -Wcovered-switch-default warnings from r314821

llvm-svn: 314826
diff --git a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
index 6cbf2a1..263b3fa 100644
--- a/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
+++ b/llvm/tools/llvm-pdbutil/MinimalSymbolDumper.cpp
@@ -290,9 +290,8 @@
 #define CV_REGISTER(name, val) RETURN_CASE(RegisterId, name, #name)
 #include "llvm/DebugInfo/CodeView/CodeViewRegisters.def"
 #undef CV_REGISTER
-    default:
-      return formatUnknownEnum(Id);
   }
+  return formatUnknownEnum(Id);
 }
 
 static std::string formatRange(LocalVariableAddrRange Range) {