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/scheduler/src/benchmarking.rs

@@ -52,8 +52,6 @@ fn fill_schedule<T: Config> (when: T::BlockNumber, n: u32) -> Result<(), &'stati
 }
 
 benchmarks! {
-	_ { }
-
 	schedule {
 		let s in 0 .. T::MaxScheduledPerBlock::get();
 		let when = BLOCK_NUMBER.into();