spkm3: remove bad kfree, unnecessary export

We're kfree()'ing something that was allocated on the stack!

Also remove an unnecessary symbol export while we're at it.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

net/sunrpc/auth_gss/gss_spkm3_seal.c

@@ -123,9 +123,6 @@ spkm3_make_token(struct spkm3_ctx *ctx,
 
 	return  GSS_S_COMPLETE;
 out_err:
-	if (md5cksum.data)
-		kfree(md5cksum.data);
-
 	token->data = NULL;
 	token->len = 0;
 	return GSS_S_FAILURE;
@@ -184,5 +181,3 @@ make_spkm3_checksum(s32 cksumtype, struct xdr_netobj *key, char *header,
 
 	return err ? GSS_S_FAILURE : 0;
 }
-
-EXPORT_SYMBOL(make_spkm3_checksum);