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/contracts/src/benchmarking/mod.rs

@@ -282,9 +282,6 @@ benchmarks! {
 		T::AccountId: AsRef<[u8]>,
 	}
 
-	_ {
-	}
-
 	// The base weight without any actual work performed apart from the setup costs.
 	on_initialize {}: {
 		Storage::<T>::process_deletion_queue_batch(Weight::max_value())