fix cppcheck warnings

src/disk_io_thread.cpp

@@ -3496,8 +3496,7 @@ namespace libtorrent
 					continue;
 				}
 
-				cached_piece_entry* pe = m_disk_cache.find_piece(j);
-				pe = m_disk_cache.add_dirty_block(j);
+				cached_piece_entry* pe = m_disk_cache.add_dirty_block(j);
 
 				if (pe == NULL)
 				{

src/peer_connection.cpp

@@ -862,9 +862,10 @@ namespace libtorrent
 		if (on_parole()) ret |= piece_picker::on_parole
 			| piece_picker::prioritize_partials;
 
-		// only one of rarest_first and sequential can be set.
-		TORRENT_ASSERT((ret & piece_picker::rarest_first) ? 1 : 0
-			+ (ret & piece_picker::sequential) ? 1 : 0 <= 1);
+		// only one of rarest_first and sequential can be set. i.e. the sum of
+		// whether the bit is set or not may only be 0 or 1 (never 2)
+		TORRENT_ASSERT(((ret & piece_picker::rarest_first) ? 1 : 0)
+			+ ((ret & piece_picker::sequential) ? 1 : 0) <= 1);
 		return ret;
 	}