HLSL: return correct error when HLSL parsing fails.

At least partially addresses issue #510.

hlsl/hlslParseHelper.cpp

@@ -119,14 +119,15 @@ bool HlslParseContext::parseShaderStrings(TPpContext& ppContext, TInputScanner&
 
     HlslScanContext scanContext(*this, ppContext);
     HlslGrammar grammar(scanContext, *this);
-    if (!grammar.parse())
-    {
+    if (!grammar.parse()) {
         // Print a message formated such that if you click on the message it will take you right to
         // the line through most UIs.
         const glslang::TSourceLoc& sourceLoc = input.getSourceLoc();
         printf("\n%s(%i): error at column %i, HLSL translation failed.\n", sourceLoc.name, sourceLoc.line,
                                                                                            sourceLoc.column);
+        return false;
     }
+
     return numErrors == 0;
 }