Remove a declaration for an unimplemented function.

Change-Id: I890cef52e9a8c26d98f227f269a7dcfcb6eaa795
diff --git a/include/cutils/partition_utils.h b/include/cutils/partition_utils.h
index 597df92..72ca80d 100644
--- a/include/cutils/partition_utils.h
+++ b/include/cutils/partition_utils.h
@@ -20,7 +20,6 @@
 __BEGIN_DECLS
 
 int partition_wiped(char *source);
-void erase_footer(const char *dev_path, long long size);
 
 __END_DECLS