Remove unnecessary casts
Some code carefully cast all data buffer arguments for BufFileWrite()
and BufFileRead() to void *, even though the arguments are already
void * (and AFAICT were never anything else). Remove this unnecessary
clutter.
Discussion: https://www.postgresql.org/message-id/flat/
11dda853-bb5b-59ba-a746-
e168b1ce4bdb%40enterprisedb.com