Cure two error leaks.
Cure two error leaks.

* subversion/libsvn_fs_fs/lock.c
  (write_digest_file, read_digest_file): Clear errors that we wish to ignore.


git-svn-id: f8a4e5e023278da1e04e203c7fe051e3c4285d88@857212 13f79535-47bb-0310-9956-ffa450edef68

wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,YueLinHo/Subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion,YueLinHo/Subversion,wbond/subversion,wbond/subversion