cryptfs: run e2fsck/fsck.f2fs in fsck domain

e2fsck and fsck.f2fs must run in the fsck domain. Add call to
setexeccon() to tell selinux to run in the fsck domain on exec.

Addresses:
avc: denied { execute_no_trans } for path="/system/bin/e2fsck" dev="mmcblk0p41" ino=241 scontext=u:r:vold:s0 tcontext=u:object_r:fsck_exec:s0 tclass=file

Bug: 26872236
Change-Id: Ib2a583aeefc667f8aa67532e0ac0ff9619b65461
diff --git a/secontext.cpp b/secontext.cpp
new file mode 100644
index 0000000..0529a30
--- /dev/null
+++ b/secontext.cpp
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <Utils.h>
+#include "secontext.h"
+
+security_context_t secontextFsck()
+{
+    return android::vold::sFsckContext;
+}