[MINOR] minor cleanups and optimizations to CLA MM primitives

src/main/java/org/apache/sysds/runtime/compress/lib/CLALibRightMultBy.java

@@ -195,28 +195,7 @@ private static CompressedMatrixBlock RMMOverlapping(CompressedMatrixBlock m1, Ma
 	}
 
 	private static void addConstant(MatrixBlock constantRow, List<AColGroup> out) {
-		// it is fairly safe to add the constant row to a column group.
-		// but it is not necessary the fastest.
-
-		// final int nCol = constantRow.getNumColumns();
-		// int bestCandidate = -1;
-		// int bestCandidateValuesSize = Integer.MAX_VALUE;
-		// for(int i = 0; i < out.size(); i++) {
-		// AColGroup g = out.get(i);
-		// if(g instanceof ColGroupDDC && g.getNumCols() == nCol && g.getNumValues() < bestCandidateValuesSize)
-		// bestCandidate = i;
-		// }
-
 		constantRow.sparseToDense();
-
-		// if(bestCandidate != -1) {
-		// AColGroup bc = out.get(bestCandidate);
-		// out.remove(bestCandidate);
-		// AColGroup ng = bc.binaryRowOpRight(new BinaryOperator(Plus.getPlusFnObject(), 1),
-		// constantRow.getDenseBlockValues(), true);
-		// out.add(ng);
-		// }
-		// else
 		out.add(ColGroupConst.create(constantRow.getDenseBlockValues()));
 	}