Fix multiplication overflow

The sd_card_info.sector_count and sd_card_info.sector_size_bytes variables are both 32 bit, so the multiplication overflows for large block devices.

Author: alrvid

libraries/BlockDevices/SDCardBlockDevice.cpp

@@ -313,7 +313,7 @@ int SDCardBlockDevice::open() {
          read_block_size = sd_card_info.sector_size_bytes;
          erase_block_size = sd_card_info.sector_size_bytes;
          write_block_size = sd_card_info.sector_size_bytes;
-         total_size = sd_card_info.sector_count * sd_card_info.sector_size_bytes;
+         total_size = (bd_size_t) sd_card_info.sector_count * (bd_size_t) sd_card_info.sector_size_bytes;
 
       }
    }