fix: rpc-server cache may not work in Windows environments (#22394)

* fix: create directory and log cache file name.

* Remove GGML_LOG_INFO conditional compilation.

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Co-authored-by: kotaro <kotaro.kusunoki@gmail.com>

tools/rpc/rpc-server.cpp

@@ -317,7 +317,7 @@ int main(int argc, char * argv[]) {
     const char * cache_dir = nullptr;
     std::string cache_dir_str;
     if (params.use_cache) {
-        cache_dir_str = fs_get_cache_directory() + "rpc/";
+        cache_dir_str = fs_get_cache_directory() + "rpc" + DIRECTORY_SEPARATOR;
         if (!fs_create_directory_with_parents(cache_dir_str)) {
             fprintf(stderr, "Failed to create cache directory: %s\n", cache_dir_str.c_str());
             return 1;