KCM: Fixed a wrong check

The pointer to the newly allocated iobuffer is stored into
state->op_ctx->reply but the check for NULL is done on state->reply,
which we already know is not NULL because it was checked before and
not modified after that.

Reviewed-by: Alexey Tikhonov <atikhono@redhat.com>
Reviewed-by: Tomáš Halman <thalman@redhat.com>
(cherry picked from commit 3cba6d1)

src/responder/kcm/kcmsrv_ops.c

@@ -161,7 +161,7 @@ struct tevent_req *kcm_cmd_send(TALLOC_CTX *mem_ctx,
                                         state,
                                         KCM_REPLY_MAX - 2*sizeof(uint32_t),
                                         KCM_REPLY_MAX - 2*sizeof(uint32_t));
-    if (state->reply == NULL) {
+    if (state->op_ctx->reply == NULL) {
         ret = ENOMEM;
         goto immediate;
     }