BUG/MINOR: listener/threads: always use atomic ops to clear the FD events

There was a leftover of the single-threaded era when removing the
FD_POLL_HUP flag from the listeners. By not using an atomic operation
to clear the flag, another thread acting on the same listener might
have lost some events, though this would have resulted in that thread
to reprocess them immediately on the next loop pass.

This should be backported as far as 1.8.

(cherry picked from commit 7cdeb61701729ef7b4d2ed97e590860478ad718d)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 6b0244049d92e960805f46c9fbdd57d5508c56f0)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed