.gitignore: Add *.o and compositortest

BUG=none
TEST=none

Change-Id: I61fb29c2c115a4f948391e497b36df1659df36ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/glbench/+/5416274
Commit-Queue: Matt Turner <msturner@google.com>
Auto-Submit: Matt Turner <msturner@google.com>
Tested-by: Matt Turner <msturner@google.com>
Reviewed-by: Po-Hsien Wang <pwang@chromium.org>
diff --git a/.gitignore b/.gitignore
index 585c612..7b549be 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
 *.d
+*.o
+compositortest
 glbench
 windowmanagertest