Fix "end of file while inside a group" error in NDK

Add the missing end of group markers to the files
which generate the "end of file while inside a group"
warning.

Bug: 183024041
Test: development/tools/ndk/build_ndk_docs.py 2>&1 \
         | grep "end of file while inside a group"
Change-Id: Ib41840bbc72651ad90aaac878d36c233b5284cf3
diff --git a/include/android/surface_control.h b/include/android/surface_control.h
index b836581..c17f822 100644
--- a/include/android/surface_control.h
+++ b/include/android/surface_control.h
@@ -467,3 +467,5 @@
 __END_DECLS
 
 #endif // ANDROID_SURFACE_CONTROL_H
+
+/** @} */