Make down-conversion explicit from CFX_ByteString to CFX_ByteStringC.

core/fxge/ge/fx_ge_ps.cpp

Index: core/fxge/ge/fx_ge_ps.cpp
diff --git a/core/fxge/ge/fx_ge_ps.cpp b/core/fxge/ge/fx_ge_ps.cpp
index 32f2fce9145c5cffc76f7fa333f26abbaa7dbd48..ec8f18e774d2ba16f73510f45d0fb2681d8f15db 100644
--- a/core/fxge/ge/fx_ge_ps.cpp
+++ b/core/fxge/ge/fx_ge_ps.cpp
@@ -680,7 +680,7 @@ FX_BOOL CFX_PSRenderer::DrawText(int nChars,
     buf << pCharPos[i].m_OriginX << " " << pCharPos[i].m_OriginY << " m";
     CFX_ByteString hex;
     hex.Format("<%02X>", ps_glyphindex);
-    buf << hex << "Tj\n";
+    buf << hex.AsByteStringC() << "Tj\n";
   }
   buf << "Q\n";
   m_pOutput->OutputPS((const FX_CHAR*)buf.GetBuffer(), buf.GetSize());