[ Upstream commit 651e9271 ]

Limit the min/max value passed to the
/proc/sys/net/ipv4/tcp_syn_retries.
Signed-off-by: Michal Tesar <mtesar@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>