BPixel has a default ctor zero'ing its members

...so no need to do that again in the body of the BPixelRaster ctor (which had
needlessly been done ever since the code's introduction with
6f769fb8 "INTEGRATION: CWS aw033").  And
BPixelRaster::reset appears to have otherwise been unused, so can be removed.

Change-Id: Icd8e09bfe225be2c6695d8a137c271dca5a70de7
Reviewed-on: https://gerrit.libreoffice.org/48184Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

include/basegfx/raster/bpixelraster.hxx

@@ -42,21 +42,13 @@ namespace basegfx
         std::unique_ptr<BPixel[]>   mpContent;
 
     public:
-        // reset
-        void reset()
-        {
-            memset(mpContent.get(), 0, sizeof(BPixel) * mnCount);
-        }
-
         // constructor/destructor
         BPixelRaster(sal_uInt32 nWidth, sal_uInt32 nHeight)
         :   mnWidth(nWidth),
             mnHeight(nHeight),
             mnCount(nWidth * nHeight),
             mpContent(new BPixel[mnCount])
-        {
-            reset();
-        }
+        {}
 
         // coordinate calcs between X/Y and span
         sal_uInt32 getIndexFromXY(sal_uInt32 nX, sal_uInt32 nY) const { return (nX + (nY * mnWidth)); }