Clean up sc-allocator (#9295)

substrate/client/allocator/src/error.rs

@@ -16,8 +16,7 @@
 // limitations under the License.
 
 /// The error type used by the allocators.
-#[derive(sp_core::RuntimeDebug)]
-#[derive(thiserror::Error)]
+#[derive(thiserror::Error, Debug)]
 pub enum Error {
 	/// Someone tried to allocate more memory than the allowed maximum per allocation.
 	#[error("Requested allocation size is too large")]

substrate/client/allocator/src/freeing_bump.rs

@@ -67,7 +67,7 @@
 //!   This is more pronounced (in terms of absolute heap amounts) with larger allocation sizes.
 
 use crate::Error;
-use sp_std::{mem, convert::{TryFrom, TryInto}, ops::{Range, Index, IndexMut}};
+use std::{mem, convert::{TryFrom, TryInto}, ops::{Range, Index, IndexMut}};
 use sp_wasm_interface::{Pointer, WordSize};
 
 /// The minimal alignment guaranteed by this allocator.