RFR : 8205959 : Do not restart close if errno is EINTR

[Ivan Gerasimov]

Hello!

When closing a socket via NET_SocketClose(int fd), a close(fd) is called.
The later is wrapped in a retry-loop, which is wrong because close() is 
not restartable.

The `man 2 close` states:
"""
... close() should not be retried after an EINTR since this may cause a 
reused descriptor from another thread to be closed.
"""

Would you please help review a trivial fix?

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8205959
WEBREV: http://cr.openjdk.java.net/~igerasim/8205959/00/webrev/

Thanks in advance!

-- 
With kind regards,
Ivan Gerasimov