MB-60458: Fix dialyzer warnings in chronicle_storage

[BenHuddleston]

In chronicle_storage we have dialyzer warnings that we cannot match a couple of clauses as the function chronicle_utils:sync_dir/1 should always return ok. One case clause can be removed, but the other is used in a generic macros which wraps various other function calls. The macro could be copied without the unneeded case, but the code re-use here seems acceptable. We could also turn the macro into a function, it's not clear if a macro is/was even necessary or appropriate here, but it's much less invasive to turn off the warning for this function.