++ cannot be used to increment an enum, so do it another way

git-svn-id: https://llvm.org/svn/llvm-project/llvdb/trunk@133781 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Interpreter/Args.cpp b/source/Interpreter/Args.cpp
index c1bc995..101a1c2 100644
--- a/source/Interpreter/Args.cpp
+++ b/source/Interpreter/Args.cpp
@@ -905,7 +905,7 @@
         {
             StreamString error_strm;
             error_strm.Printf ("Invalid format character or name '%s'. Valid values are:\n", s);
-            for (Format f = eFormatDefault; f < kNumFormats; ++f)
+            for (Format f = eFormatDefault; f < kNumFormats; f = Format(f+1))
             {
                 char format_char = FormatManager::GetFormatAsFormatChar(f);
                 if (format_char)