build fialed on GNU/Linux

[fpliu]

In function ‘open’,
    inlined from ‘save_file’ at svnup.c:1226:13,
    inlined from ‘get_files’ at svnup.c:2149:11,
    inlined from ‘main’ at svnup.c:3003:4:
/usr/include/x86_64-linux-gnu/bits/fcntl2.h:50:11: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
   50 |           __open_missing_mode ();
      |           ^~~~~~~~~~~~~~~~~~~~~~
In function ‘open’,
    inlined from ‘save_known_file_list’ at svnup.c:1263:12,
    inlined from ‘main’ at svnup.c:3022:2:
/usr/include/x86_64-linux-gnu/bits/fcntl2.h:50:11: error: call to ‘__open_missing_mode’ declared with attribute error: open with O_CREAT or O_TMPFILE in second argument needs 3 arguments
   50 |           __open_missing_mode ();
      |           ^~~~~~~~~~~~~~~~~~~~~~

https://github.com/rofl0r/svn-lite/blob/r/svnup.c#L1191
https://github.com/rofl0r/svn-lite/blob/r/svnup.c#L1217
https://github.com/rofl0r/svn-lite/blob/r/svnup.c#L2282

int open(const char *pathname, int flags, mode_t mode);