graphics: clang-format allocator default impl

Test: builds
Change-Id: I01cee2e7bc778f2e3e540a9856c25f1a0e390186
diff --git a/graphics/allocator/2.0/default/Gralloc.h b/graphics/allocator/2.0/default/Gralloc.h
index c79eeaa..18c5202 100644
--- a/graphics/allocator/2.0/default/Gralloc.h
+++ b/graphics/allocator/2.0/default/Gralloc.h
@@ -28,11 +28,11 @@
 
 extern "C" IAllocator* HIDL_FETCH_IAllocator(const char* name);
 
-} // namespace implementation
-} // namespace V2_0
-} // namespace allocator
-} // namespace graphics
-} // namespace hardware
-} // namespace android
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace allocator
+}  // namespace graphics
+}  // namespace hardware
+}  // namespace android
 
-#endif // ANDROID_HARDWARE_GRAPHICS_ALLOCATOR_V2_0_GRALLOC_H
+#endif  // ANDROID_HARDWARE_GRAPHICS_ALLOCATOR_V2_0_GRALLOC_H