Tweak comment wording (#18007)

* Revert "Update ReactFiberExpirationTime.js (#17825)"

This reverts commit b63cb6f.

* Reword

packages/react-reconciler/src/ReactFiberExpirationTime.js

@@ -43,7 +43,7 @@ const MAGIC_NUMBER_OFFSET = Batched - 1;
 
 // 1 unit of expiration time represents 10ms.
 export function msToExpirationTime(ms: number): ExpirationTime {
- // Always subtract an offset so that we don't clash with the magic number for NoWork.
+ // Always subtract from the offset so that we don't clash with the magic number for NoWork.
  return MAGIC_NUMBER_OFFSET - ((ms / UNIT_SIZE) | 0);
 }