fix units

Author: netrunnereve

ggml/src/ggml-vulkan/ggml-vulkan.cpp

@@ -839,7 +839,7 @@ class vk_perf_logger {
             for (const auto& time : t.second) {
                 total += time;
             }
-            std::cerr << t.first << ": " << t.second.size() << " x " << (total / t.second.size() / 1000.0) << " ms" << std::endl;
+            std::cerr << t.first << ": " << t.second.size() << " x " << (total / t.second.size() / 1000.0) << " us" << std::endl;
         }
 
         timings.clear();