Fix output of pointers for 64bit devices.

Change-Id: I279c1cf8d4c126b98f4a92ca807ade3749d01ff0
diff --git a/libs/binder/TextOutput.cpp b/libs/binder/TextOutput.cpp
index db3e858..2ed5188 100644
--- a/libs/binder/TextOutput.cpp
+++ b/libs/binder/TextOutput.cpp
@@ -116,8 +116,8 @@
 
 TextOutput& operator<<(TextOutput& to, const void* val)
 {
-    char buf[16];
-    sprintf(buf, "%p", val);
+    char buf[32];
+    snprintf(buf, sizeof(buf), "%p", val);
     to.print(buf, strlen(buf));
     return to;
 }