silence android warning

git-svn-id: http://skia.googlecode.com/svn/trunk@8567 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ErrorTest.cpp b/tests/ErrorTest.cpp
index cbaf9d1..c3b1153 100644
--- a/tests/ErrorTest.cpp
+++ b/tests/ErrorTest.cpp
@@ -18,7 +18,7 @@
      SkClearLastError();                                                      \
   }
                        
-void cb(SkError err, void *context) {
+static void cb(SkError err, void *context) {
     int *context_ptr = static_cast<int *>(context);
     SkDebugf("CB (0x%x): %s\n", *context_ptr, SkGetLastErrorString());
 }