Properly exit ODBC with 'X', allow linking on BSD/OS.

src/interfaces/odbc/GNUmakefile

src/interfaces/odbc/bind.c

src/interfaces/odbc/columninfo.c

src/interfaces/odbc/connection.c

src/interfaces/odbc/convert.c

src/interfaces/odbc/dlg_specific.c

src/interfaces/odbc/drvconn.c

src/interfaces/odbc/environ.c

src/interfaces/odbc/execute.c

src/interfaces/odbc/info.c

src/interfaces/odbc/lobj.c

src/interfaces/odbc/misc.c

src/interfaces/odbc/options.c

src/interfaces/odbc/parse.c

src/interfaces/odbc/pgtypes.c

src/interfaces/odbc/psqlodbc.c

src/interfaces/odbc/qresult.c

src/interfaces/odbc/results.c

src/interfaces/odbc/setup.c

src/interfaces/odbc/socket.c