gdiplus: Add a stub for GdipSetLineLinearBlend.

dlls/gdiplus/brush.c

@@ -664,3 +664,14 @@ GpStatus WINGDIPAPI GdipSetLineColors(GpLineGradient *brush, ARGB color1,
 
     return NotImplemented;
 }
+
+GpStatus WINGDIPAPI GdipSetLineLinearBlend(GpLineGradient *brush, REAL focus,
+    REAL scale)
+{
+    static int calls;
+
+    if(!(calls++))
+        FIXME("not implemented\n");
+
+    return NotImplemented;
+}

dlls/gdiplus/gdiplus.spec

@@ -538,7 +538,7 @@
 @ stdcall GdipSetLineBlend(ptr ptr ptr long)
 @ stdcall GdipSetLineColors(ptr long long)
 @ stdcall GdipSetLineGammaCorrection(ptr long)
-@ stub GdipSetLineLinearBlend
+@ stdcall GdipSetLineLinearBlend(ptr long long)
 @ stub GdipSetLinePresetBlend
 @ stdcall GdipSetLineSigmaBlend(ptr long long)
 @ stub GdipSetLineTransform