packagefs: Prevent signed integer overflow in Query::IndexGetWeightedScore.

As the comment already noted, the maximum input score is 2048,
and 2048*1024*1024 overflows int32. Subtract 1 from maxFactor
to prevent this.

src/add-ons/kernel/file_systems/packagefs/indices/Query.cpp

@@ -97,10 +97,9 @@ struct Query::QueryPolicy {
 	{
 		// should be inversely proportional to the index size; max input score
 		// is 2048
-		static const int32 maxFactor = 1024 * 1024;
+		static const int32 maxFactor = (1024 * 1024) - 1;
-		return score * (maxFactor
+		return score * (maxFactor /
-			/ std::min(maxFactor,
+			std::min(maxFactor, std::max((int32)1, index.index->CountEntries())));
-				std::max((int32)1, index.index->CountEntries())));
 	}
 
 	static type_code IndexGetType(Index& index)