The explain_lseek_or_die function is used to call the lseek(2) system call. On failure an explanation
will be printed to stderr, obtained from explain_lseek(3), and then the process terminates by calling
exit(EXIT_FAILURE).
This function is intended to be used in a fashion similar to the following example:
long long result = explain_lseek_or_die(fildes, offset, whence);
fildes The fildes, exactly as to be passed to the lseek(2) system call.
offset The offset, exactly as to be passed to the lseek(2) system call.
whence The whence, exactly as to be passed to the lseek(2) system call.
Returns:
On successful, returns the resulting offset location as measured in bytes from the beginning of
the file. On failure, prints an explanation and exits.