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>

substrate/frame/babe/src/benchmarking.rs

@@ -23,8 +23,6 @@ use frame_benchmarking::benchmarks;
 type Header = sp_runtime::generic::Header<u64, sp_runtime::traits::BlakeTwo256>;
 
 benchmarks! {
-	_ {	}
-
 	check_equivocation_proof {
 		let x in 0 .. 1;