libbufferhubqueue: Fix syntax in Android.bp

There was a spelling mistake for cflags property of libbufferhub
cc_library object.

Bug: None
Test: `m -j32` succeeds
Change-Id: I862c2266d86586469dc7299bf727f75bb3df6512
(cherry picked from commit 66fd7cb0f3b1a70121fb223b27a51f06534ebc46)
diff --git a/libs/vr/libbufferhubqueue/Android.bp b/libs/vr/libbufferhubqueue/Android.bp
index 2d96638..0fa1f01 100644
--- a/libs/vr/libbufferhubqueue/Android.bp
+++ b/libs/vr/libbufferhubqueue/Android.bp
@@ -42,7 +42,7 @@
 
 cc_library {
     name: "libbufferhubqueue",
-    cflags = [
+    cflags: [
         "-DLOG_TAG=\"libbufferhubqueue\"",
         "-DTRACE=0",
     ],