Remove duplicate member of GrVkDrawableInfo struct.

Bug: skia:
Change-Id: I81a38f9920f89f4749fc58458b85a29714cec7a9
Reviewed-on: https://skia-review.googlesource.com/c/174584
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
diff --git a/tests/VkDrawableTest.cpp b/tests/VkDrawableTest.cpp
index d9aa8b6..8bb1251 100644
--- a/tests/VkDrawableTest.cpp
+++ b/tests/VkDrawableTest.cpp
@@ -67,7 +67,7 @@
 
             VkClearAttachment attachment;
             attachment.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
-            attachment.colorAttachment = vkInfo.fImageAttachmentIndex;
+            attachment.colorAttachment = vkInfo.fColorAttachmentIndex;
             attachment.clearValue.color = vkColor;
 
             GR_VK_CALL(fInterface, CmdClearAttachments(vkInfo.fSecondaryCommandBuffer,