fix : remove _{ } syntax from benchmark macro (#7822)

* commented use of common

* hack to pass tests

* another hack

* remove all commented code

* fix the easy tests

* temp hack

* follow through comma hack until better solution

* patch macro

* missed one

* update benchmarks

* update docs

* fix docs

* removed too much

* fix changes

Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>

src/benchmarking.rs

@@ -42,8 +42,7 @@ fn assert_last_event<T: Config<I>, I: Instance>(generic_event: <T as Config<I>>:
 }
 
 benchmarks_instance! {
-	_{ }
-
+
 	set_members {
 		let m in 1 .. T::MaxMembers::get();
 		let n in 1 .. T::MaxMembers::get();