NFS: fix unsigned comparison in nfs4_create_sec_client

fs/nfs/nfs4namespace.c: In function ‘nfs4_create_sec_client’:
fs/nfs/nfs4namespace.c:171:2: error: comparison of unsigned expression < 0 is always false [-Werror=type-limits]

Introduced by commit 72de53ec4bca39c26709122a8f78bfefe7b6bca4
"NFS: Do secinfo as part of lookup"

Signed-off-by: Benny Halevy <bhalevy@tonian.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index a7f3ded..3f5519b 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -168,7 +168,7 @@
 	rpc_authflavor_t flavor;
 
 	flavor = nfs4_negotiate_security(inode, name);
-	if (flavor < 0)
+	if ((int)flavor < 0)
 		return ERR_PTR(flavor);
 
 	clone = rpc_clone_client(clnt);