libc syslog, syslogd, logger, uds fixes

libc syslog, syslogd, logger, uds fixes

changes necessary for libc syslog() using a unix domain socket.

	. libc syslog: don't use send() connect() for unix
	  datagram sockets, minix wants write() and ioctl()
	. syslogd: listen on _PATH_LOG unix domain socket
	. logger: warnings fixes
	. pfs: make uds dgram socket type nonblocking so
	  syslog() doesn't block
	. vfs: add sanity check for empty fd in unpause()

Change-Id: Ied136c6fe0cc288f5a53478f1eebccc1ab1f39fb