Fix use-after-free of stack-allocated temporary string.

am: c41b838baa

Change-Id: I3eac4b22b885e7991256e5a7df8f37e6b9a10cce

init/selinux.cpp

@@ -295,13 +295,15 @@ bool LoadSplitPolicy() {
         return false;
     }
     std::string mapping_file("/system/etc/selinux/mapping/" + vend_plat_vers + ".cil");
+    const std::string version_as_string = std::to_string(max_policy_version);
+
     // clang-format off
     const char* compile_args[] = {
         "/system/bin/secilc",
         plat_policy_cil_file,
         "-M", "true", "-G", "-N",
         // Target the highest policy language version supported by the kernel
-        "-c", std::to_string(max_policy_version).c_str(),
+        "-c", version_as_string.c_str(),
         mapping_file.c_str(),
         "/vendor/etc/selinux/nonplat_sepolicy.cil",
         "-o", compiled_sepolicy,