Incorrect comment in postgres_fdw.c

I think the following comment for store_returning_result() in
postgres_fdw.c is not right.

    /* PGresult must be released before leaving this function. */

I think PGresult should not be released before leaving this function *on
success* in that function.

(I guess the comment has been copied and pasted from that for
get_remote_estimate().)

Thanks,

Best regards,
Etsuro Fujita