dccp: return -EINVAL on invalid feature length

dccp: return -EINVAL on invalid feature length

[ Upstream commit: 19443178fbfbf40db15c86012fc37df1a44ab857 ]

dccp_feat_change() validates length and on error is returning 1.
This happens to work since call chain is checking for 0 == success,
but this is returned to userspace, so make it a real error value.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>