net/sctp/socket.c: squish warning

net/sctp/socket.c: In function 'sctp_setsockopt_autoclose':
net/sctp/socket.c:2090: warning: comparison is always false due to limited range of data type

Cc: Andrei Pelinescu-Onciul <andrei@iptel.org>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>