Correctly handle mat2x2 in Vulkan

src/gpu/vk/GrVkPipelineStateDataManager.cpp

Index: src/gpu/vk/GrVkPipelineStateDataManager.cpp
diff --git a/src/gpu/vk/GrVkPipelineStateDataManager.cpp b/src/gpu/vk/GrVkPipelineStateDataManager.cpp
index 9fa6d6dea2e7751249ee87d66014881578256209..5711df313207c73a7a616c2dda87aa12d524bba8 100644
--- a/src/gpu/vk/GrVkPipelineStateDataManager.cpp
+++ b/src/gpu/vk/GrVkPipelineStateDataManager.cpp
@@ -233,12 +233,10 @@ template<int N> struct set_uniform_matrix {
         buffer = static_cast<char*>(buffer) + uniformOffset;
         for (int i = 0; i < count; ++i) {
             const float* matrix = &matrices[N * N * i];
-            memcpy(buffer, &matrix[0], N * sizeof(float));
-            buffer = static_cast<char*>(buffer) + 4*sizeof(float);
-            memcpy(buffer, &matrix[3], N * sizeof(float));
-            buffer = static_cast<char*>(buffer) + 4*sizeof(float);
-            memcpy(buffer, &matrix[6], N * sizeof(float));
-            buffer = static_cast<char*>(buffer) + 4*sizeof(float);
+            for (int j = 0; j < N; ++j) {
+                memcpy(buffer, &matrix[j * N], N * sizeof(float));
+                buffer = static_cast<char*>(buffer) + 4 * sizeof(float);
+            }
         }
     }
 };