sctp: fix an error code in sctp_sf_eat_auth()

The sctp_sf_eat_auth() function is supposed to enum sctp_disposition
values and returning a kernel error code will cause issues in the
caller.  Change -ENOMEM to SCTP_DISPOSITION_NOMEM.

Fixes: 65b07e5d ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sctp/sm_statefuns.c

@@ -4482,7 +4482,7 @@ enum sctp_disposition sctp_sf_eat_auth(struct net *net,
 				    SCTP_AUTH_NEW_KEY, GFP_ATOMIC);
 
 		if (!ev)
-			return -ENOMEM;
+			return SCTP_DISPOSITION_NOMEM;
 
 		sctp_add_cmd_sf(commands, SCTP_CMD_EVENT_ULP,
 				SCTP_ULPEVENT(ev));