SplashGouraudPattern: Remove mode member variable

We don't need it anymore, was introduced in the initial overprint implementation and was forgotten to be removed when merging xpdf 3.03
diff --git a/poppler/SplashOutputDev.cc b/poppler/SplashOutputDev.cc
index 50b7824..efc0aae 100644
--- a/poppler/SplashOutputDev.cc
+++ b/poppler/SplashOutputDev.cc
@@ -197,15 +197,10 @@
 // SplashGouraudPattern
 //------------------------------------------------------------------------
 SplashGouraudPattern::SplashGouraudPattern(GBool bDirectColorTranslationA,
-                                           GfxState *stateA, GfxGouraudTriangleShading *shadingA, SplashColorMode modeA) {
-  SplashColor defaultColor;
-  GfxColor srcColor;
+                                           GfxState *stateA, GfxGouraudTriangleShading *shadingA) {
   state = stateA;
   shading = shadingA;
-  mode = modeA;
   bDirectColorTranslation = bDirectColorTranslationA;
-  shadingA->getColorSpace()->getDefaultColor(&srcColor);
-  convertGfxColor(defaultColor, mode, shadingA->getColorSpace(), &srcColor);
   gfxMode = shadingA->getColorSpace()->getMode();
 }
 
@@ -4754,7 +4749,7 @@
   }
   // restore vector antialias because we support it here
   if (shading->isParameterized()) {
-    SplashGouraudColor *splashShading = new SplashGouraudPattern(bDirectColorTranslation, state, shading, colorMode);
+    SplashGouraudColor *splashShading = new SplashGouraudPattern(bDirectColorTranslation, state, shading);
     GBool vaa = getVectorAntialias();
     GBool retVal = gFalse;
     setVectorAntialias(gTrue);
diff --git a/poppler/SplashOutputDev.h b/poppler/SplashOutputDev.h
index 4dc97e8..3a5883c 100644
--- a/poppler/SplashOutputDev.h
+++ b/poppler/SplashOutputDev.h
@@ -135,9 +135,9 @@
 class SplashGouraudPattern: public SplashGouraudColor {
 public:
 
-  SplashGouraudPattern(GBool bDirectColorTranslation, GfxState *state, GfxGouraudTriangleShading *shading, SplashColorMode mode);
+  SplashGouraudPattern(GBool bDirectColorTranslation, GfxState *state, GfxGouraudTriangleShading *shading);
 
-  SplashPattern *copy() override { return new SplashGouraudPattern(bDirectColorTranslation, state, shading, mode); }
+  SplashPattern *copy() override { return new SplashGouraudPattern(bDirectColorTranslation, state, shading); }
 
   ~SplashGouraudPattern();
 
@@ -162,7 +162,6 @@
   GfxGouraudTriangleShading *shading;
   GfxState *state;
   GBool bDirectColorTranslation;
-  SplashColorMode mode;
   GfxColorSpaceMode gfxMode;
 };