forgotten ComputeScanlineSize() (tdf#140917)

Change-Id: Id139cea52832b7973dfac47d309d5bba8299b4e1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/112263
Reviewed-by: Mark Hung <marklh9@gmail.com>
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>
Tested-by: Jenkins
diff --git a/vcl/skia/salbmp.cxx b/vcl/skia/salbmp.cxx
index 68d2f9a..b94debc 100644
--- a/vcl/skia/salbmp.cxx
+++ b/vcl/skia/salbmp.cxx
@@ -388,6 +388,7 @@
    if (mEraseColorSet)
    { // Simple.
        mSize = mPixelsSize = newSize;
        ComputeScanlineSize();
        EraseInternal(mEraseColor);
        return true;
    }