Newer GCC versions raise an undefined behaviour warning in
fat_chksum() because it overruns the name buffer. However, this is
intentional behaviour because the extension array immediately follows.
Refactor this function to avoid the warning and make it clear it's
checksumming both parts.
Newer GCC versions raise an undefined behaviour warning in
fat_chksum() because it overruns the name buffer. However, this is
intentional behaviour because the extension array immediately follows.
Refactor this function to avoid the warning and make it clear it's
checksumming both parts.
