vulkan: fix uniform buffer descriptor

There was a bug where the count of used builtin uniform buffer objects
was not advanced. This caused another problem since vulkan requires
a certain alignment for the buffer. This commit fixes both of those
things.

src/modules/graphics/vulkan/Shader.h

@@ -52,11 +52,13 @@ namespace love {
 				void setMainTex(graphics::Texture* texture);
 
 			private:
+				void calculateUniformBufferSizeAligned();
 				void compileShaders();
 				void createDescriptorSetLayout();
 				void createPipelineLayout();
 				void createStreamBuffers();
 
+				VkDeviceSize uniformBufferSizeAligned;
 				PFN_vkCmdPushDescriptorSetKHR vkCmdPushDescriptorSet;
 
 				VkDescriptorSetLayout descriptorSetLayout;