ggml-zdnn: fix ztensor deallocation abort

stabilise ggml <-> zdnn api

Signed-off-by: Aaron Teo <[email protected]>

Author: taronaeo

ggml/src/ggml-zdnn/ggml-zdnn-rewrite.cpp

@@ -379,7 +379,9 @@ static void ggml_backend_zdnn_buffer_free_buffer(ggml_backend_buffer_t buffer) {
     ggml_backend_zdnn_buffer_context * ctx = (ggml_backend_zdnn_buffer_context *)buffer->context;
 
     for (int i = 0; i < ctx->n_buffers; i++) {
-        ZDNN_CHECK(zdnn_free_ztensor_buffer(&ctx->buffers[i]->ztensor));
+        if (ctx->buffers[i]->ztensor.buffer != NULL && ctx->buffers[i]->ztensor.is_transformed) {
+            ZDNN_CHECK(zdnn_free_ztensor_buffer(&ctx->buffers[i]->ztensor));
+        }
     }
 
     delete ctx;