pgsql: Remove unnecessary (char *) casts [checksum]

Remove unnecessary (char *) casts [checksum]

Remove some (char *) casts related to uses of the pg_checksum_page()
function. These casts are useless, because everything involved
already has the right type. Moreover, these casts actually silently
discarded a const qualifier. The declaration of a higher-level
function needs to be adjusted to fix that.

Reviewed-by: Dagfinn Ilmari Mannsåker <ilmari(at)ilmari(dot)org>
Discussion: https://www.postgresql.org/message-id/flat/fd1fcedb-3492-4fc8-9e3e-74b97f2db6c7%40eisentraut.org

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/1b5841d4615045e48c3a0019e36f91e4e71d0912

Modified Files
--------------
contrib/pageinspect/rawpage.c | 2 +-
src/backend/storage/page/bufpage.c | 6 +++---
src/include/storage/bufpage.h | 2 +-
3 files changed, 5 insertions(+), 5 deletions(-)