init: Simplify struct BuiltinArguments

Make the code that creates BuiltinArguments instances easier to read by
using initializer lists instead of constructor calls. Remove the
BuiltinArguments constructors.

Change-Id: I6cf215a81d298cf7e524e22fb75db820e0225c9a
Signed-off-by: Bart Van Assche <bvanassche@google.com>
diff --git a/init/builtins.cpp b/init/builtins.cpp
index a89813e..bc23972 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -1074,7 +1074,7 @@
 static Result<void> do_restorecon_recursive(const BuiltinArguments& args) {
     std::vector<std::string> non_const_args(args.args);
     non_const_args.insert(std::next(non_const_args.begin()), "--recursive");
-    return do_restorecon({std::move(non_const_args), args.context});
+    return do_restorecon({.args = std::move(non_const_args), .context = args.context});
 }
 
 static Result<void> do_loglevel(const BuiltinArguments& args) {