Make priviledged functions explicity use origin (#3045)

* Make priviledged functions explicity use `origin`

* Fix typo in docs

* Fix more tests

* Remove `root` pathway, add semicolons

substrate/srml/support/test/tests/instance.rs

@@ -53,7 +53,8 @@ mod module1 {
 
 			fn deposit_event<T, I>() = default;
 
-			fn one() {
+			fn one(origin) {
+				system::ensure_root(origin)?;
 				Self::deposit_event(RawEvent::AnotherVariant(3));
 			}
 		}

substrate/srml/support/test/tests/reserved_keyword/on_initialize.rs

@@ -19,7 +19,7 @@ macro_rules! reserved {
 
 				srml_support::decl_module! {
 					pub struct Module<T: Trait> for enum Call where origin: T::Origin {
-						fn $reserved() -> Result { unreachable!() }
+						fn $reserved(_origin) -> Result { unreachable!() }
 					}
 				}
 			}