knfsd: allow cache_register to return error on failure

Newer server features such as nfsv4 and gss depend on proc to work, so a
failure to initialize the proc files they need should be treated as
fatal.

Thanks to Andrew Morton for style fix and compile fix in case where
CONFIG_NFSD_V4 is undefined.

Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c
index d329a12..aa790bb 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -1386,10 +1386,19 @@
 gss_svc_init(void)
 {
 	int rv = svc_auth_register(RPC_AUTH_GSS, &svcauthops_gss);
-	if (rv == 0) {
-		cache_register(&rsc_cache);
-		cache_register(&rsi_cache);
-	}
+	if (rv)
+		return rv;
+	rv = cache_register(&rsc_cache);
+	if (rv)
+		goto out1;
+	rv = cache_register(&rsi_cache);
+	if (rv)
+		goto out2;
+	return 0;
+out2:
+	cache_unregister(&rsc_cache);
+out1:
+	svc_auth_unregister(RPC_AUTH_GSS);
 	return rv;
 }