initialize backend to nullptr

Author: stduhpf

tools/mtmd/clip.cpp

@@ -367,8 +367,8 @@ struct clip_ctx {
     std::vector<ggml_backend_t> backend_ptrs;
     std::vector<ggml_backend_buffer_type_t> backend_buft;
 
-    ggml_backend_t backend;
-    ggml_backend_t backend_cpu;
+    ggml_backend_t backend = nullptr;
+    ggml_backend_t backend_cpu = nullptr;
     ggml_backend_buffer_ptr buf;
 
     int max_nodes = 8192;
@@ -384,7 +384,6 @@ struct clip_ctx {
         if (!backend_cpu) {
             throw std::runtime_error("failed to initialize CPU backend");
         }
-        backend = nullptr;
         if (ctx_params.use_gpu) {
             auto backend_name = std::getenv("MTMD_BACKEND_DEVICE");
             if (backend_name != nullptr) {