xdrgen: Remove check for "nfs_ok" in C templates

Obviously, "nfs_ok" is defined only for NFS protocols. Other XDR
protocols won't know "nfs_ok" from Adam.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: chucklever

tools/net/sunrpc/xdrgen/templates/C/program/decoder/result.j2

@@ -13,7 +13,7 @@ static int {{ program }}_xdr_dec_{{ result }}(struct rpc_rqst *req,
 
 	if (!xdrgen_decode_{{ result }}(xdr, result))
 		return -EIO;
-	if (result->stat != nfs_ok)
+	if (result->stat)
 		return {{ program }}_stat_to_errno(result->stat);
 {% endif %}
 	return 0;