MFC rev 1.89

MFC rev 1.89
  Bring following change from FreeBSD (yar@freebsd.org):
    uipc_syscall.c rev 1.154

    If connect(2) has been interrupted by a signal and therefore the
    connection is to be established asynchronously, behave as in the
    case of non-blocking mode:

    - keep the SS_ISCONNECTING bit set thus indicating that
      the connection establishment is in progress, which is the case
      (clearing the bit in this case was just a bug);

    - return EALREADY, instead of the confusing and unreasonable
      EADDRINUSE, upon further connect(2) attempts on this socket
      until the connection is established (this also brings our
      connect(2) into accord with IEEE Std 1003.1.)

  Tested-by: y0netan1@
  Reviewed-by: hsu@
  Dragonfly-bug: <http://bugs.dragonflybsd.org/issue1079>