Ticket #48822 - (389-ds-base-1.3.5) Fixing coverity issues.
    
    Description: DEADCODE -- slapd/plugin.c:541: dead_error_line: Execution
    cannot reach the expression "rc != 0" inside this statement: "if (lderr
    == -2 || rc != 0)...".
    
    (lderr == SLAPI_PLUGIN_EXTENDED_NOT_HANDLED) is always true, thus if
    rc == LDAP_SUCCESS, the value is returned instead of the default error
    code SLAPI_PLUGIN_EXTENDED_NOT_HANDLED.
    
    https://fedorahosted.org/389/ticket/48822
    
    Reviewed by wibrown@redhat.com (Thank you, William!!)