sunrpc: return better error in svcauth_gss_accept() on alloc failure

This ends up returning AUTH_BADCRED when memory allocation fails today.
Fix it to return AUTH_FAILED, which better indicates a failure on the
server.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: jtlayton

net/sunrpc/auth_gss/svcauth_gss.c

@@ -1628,7 +1628,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp)
 	int		ret;
 	struct sunrpc_net *sn = net_generic(SVC_NET(rqstp), sunrpc_net_id);
 
-	rqstp->rq_auth_stat = rpc_autherr_badcred;
+	rqstp->rq_auth_stat = rpc_autherr_failed;
 	if (!svcdata)
 		svcdata = kmalloc(sizeof(*svcdata), GFP_KERNEL);
 	if (!svcdata)
@@ -1638,6 +1638,7 @@ svcauth_gss_accept(struct svc_rqst *rqstp)
 	svcdata->rsci = NULL;
 	gc = &svcdata->clcred;
 
+	rqstp->rq_auth_stat = rpc_autherr_badcred;
 	if (!svcauth_gss_decode_credbody(&rqstp->rq_arg_stream, gc, &rpcstart))
 		goto auth_err;
 	if (gc->gc_v != RPC_GSS_VERSION)