Fixed path in VirtualSwapchainLayer.json

In order for the vulkan loader to find it, the path must be
relative to the json file.

Test: Ran gapir on x86_64 successfully.

Change-Id: I83961491d1634d7b7502364241a94098fe57ec61
diff --git a/cc/vulkan_layers/vk_virtual_swapchain/VirtualSwapchainLayer.json b/cc/vulkan_layers/vk_virtual_swapchain/VirtualSwapchainLayer.json
index ea06d09..dfbe2b2 100644
--- a/cc/vulkan_layers/vk_virtual_swapchain/VirtualSwapchainLayer.json
+++ b/cc/vulkan_layers/vk_virtual_swapchain/VirtualSwapchainLayer.json
@@ -3,7 +3,7 @@
   "layer": {
     "name": "VirtualSwapchain",
     "type": "GLOBAL",
-    "library_path": "libVkLayer_VirtualSwapchain.so",
+    "library_path": "./libVkLayer_VirtualSwapchain.so",
     "api_version" : "1.0.5",
     "implementation_version" : "1",
     "description" : "Virtual Swapchain Layer",