s3: Mark sockets in error state writable

s3: Mark sockets in error state writable

Without this patch, when a socket only has a write event pending, we will never
detect an error condition. I've seen winbind doing

12:19:13.659964 gettimeofday({1306837153, 659984}, NULL) = 0 <0.000016>
12:19:13.660109 poll([{fd=35, events=POLLOUT}, {fd=32, events=POLLIN|POLLHUP}], 2, 9996) = 1 ([{fd=35, revents=POLLERR|POLLHUP}]) <0.000015>
12:19:13.660253 gettimeofday({1306837153, 660269}, NULL) = 0 <0.000013>
12:19:13.660298 poll([{fd=35, events=POLLOUT}, {fd=32, events=POLLIN|POLLHUP}], 2, 9996) = 1 ([{fd=35, revents=POLLERR|POLLHUP}]) <0.000015>

for a while when trying to connect to a DC when the socket had died already.

Volker

Autobuild-User: Volker Lendecke <vlendec@samba.org>
Autobuild-Date: Tue May 31 20:59:10 CEST 2011 on sn-devel-104