Set the delimiting byte used to mark the end of a record in the backing
source file for the Recno access method.
This byte is used for variable length records, if the re_source
file is specified. If the re_source file is specified and no
delimiting byte was specified, <newline> characters (i.e.
ASCII 0x0a) are interpreted as end-of-record markers.
The DB->set_re_delim interface may only be used to configure Berkeley DB before
the DB->open interface is called.
The DB->set_re_delim function returns a non-zero error value on failure and 0 on success.