Avoid a potential null-pointer dereference in an error path.
Avoid a potential null-pointer dereference in an error path.

* subversion/libsvn_wc/wc_db.c
  (svn_wc__db_read_pristine_info):  Only attempt to recreate an error if it
    exists, otherwise just use an existing error.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion