Use freecon() with getcon()/getfilecon().

Bug: https://issuetracker.google.com/175090444
Test: treehugger
Change-Id: Ia2b8102f1c9a4fd56ec1ff026ba5b4f375102b9b
diff --git a/init/service.cpp b/init/service.cpp
index 766eb5d..d84dcd4 100644
--- a/init/service.cpp
+++ b/init/service.cpp
@@ -72,12 +72,12 @@
     if (getcon(&raw_con) == -1) {
         return Error() << "Could not get security context";
     }
-    std::unique_ptr<char> mycon(raw_con);
+    std::unique_ptr<char, decltype(&freecon)> mycon(raw_con, freecon);
 
     if (getfilecon(service_path.c_str(), &raw_filecon) == -1) {
         return Error() << "Could not get file context";
     }
-    std::unique_ptr<char> filecon(raw_filecon);
+    std::unique_ptr<char, decltype(&freecon)> filecon(raw_filecon, freecon);
 
     char* new_con = nullptr;
     int rc = security_compute_create(mycon.get(), filecon.get(),