Allow pallet::call to return DispatchResult (#8241)

* allow dispatch result

* remove custom error message

* format

* add forgotten UI test

* fix test

* fix tests

substrate/frame/support/src/lib.rs

@@ -1078,7 +1078,7 @@ pub mod pallet_prelude {
 		Twox128, Blake2_256, Blake2_128, Identity, Twox64Concat, Blake2_128Concat, ensure,
 		RuntimeDebug, storage,
 		traits::{Get, Hooks, IsType, GetPalletVersion, EnsureOrigin},
-		dispatch::{DispatchResultWithPostInfo, Parameter, DispatchError},
+		dispatch::{DispatchResultWithPostInfo, Parameter, DispatchError, DispatchResult},
 		weights::{DispatchClass, Pays, Weight},
 		storage::types::{StorageValue, StorageMap, StorageDoubleMap, ValueQuery, OptionQuery},
 	};
@@ -1244,7 +1244,7 @@ pub mod pallet_prelude {
 /// 		$some_arg: $some_type,
 /// 		// or with compact attribute: #[pallet::compact] $some_arg: $some_type,
 /// 		...
-/// 	) -> DispatchResultWithPostInfo {
+/// 	) -> DispatchResultWithPostInfo { // or `-> DispatchResult`
 /// 		...
 /// 	}
 /// 	...
@@ -1255,7 +1255,8 @@ pub mod pallet_prelude {
 ///
 /// Each dispatchable needs to define a weight with `#[pallet::weight($expr)]` attribute,
 /// the first argument must be `origin: OriginFor<T>`, compact encoding for argument can be used
-/// using `#[pallet::compact]`, function must return DispatchResultWithPostInfo.
+/// using `#[pallet::compact]`, function must return `DispatchResultWithPostInfo` or
+/// `DispatchResult`.
 ///
 /// All arguments must implement `Debug`, `PartialEq`, `Eq`, `Decode`, `Encode`, `Clone`. For ease
 /// of use, bound the trait `Member` available in frame_support::pallet_prelude.