Use ENOSYS rather than EINVAL for fd_send/fd_recv.
Use ENOSYS rather than EINVAL for fd_send/fd_recv.

LTD-Beget/dovecot,LTD-Beget/dovecot,damoxc/dovecot,Distrotech/dovecot,LTD-Beget/dovecot,Distrotech/dovecot,Distrotech/dovecot,damoxc/dovecot,Distrotech/dovecot,Distrotech/dovecot,damoxc/dovecot,damoxc/dovecot,LTD-Beget/dovecot,LTD-Beget/dovecot,damoxc/dovecot