Ghc 8.10.1 changelog typos

• are either individually buildable or squashed
• have commit messages which describe what they do (referring to [Notes][notes] and tickets using #NNNN syntax when appropriate)
• have added source comments describing your change. For larger changes you likely should add a [Note][notes] and cross-reference it from the relevant places.
• add a testcase to the testsuite.
• replace this message with a description motivating your change

Reading the GHC 8.10.1 User's Guide I found a couple typos in section 3.2.5 Runtime system of the release notes.