pgsql: Make error message of pageinspect more consistent for raw page i

Make error message of pageinspect more consistent for raw page inputs

There is a copy-paste error from bt_page_items() which got into
bt_page_items_bytea(). A second message in get_raw_page_internal() was
inconsistent with all the other sub-modules.

Author: Ashutosh Sharma
Discussion: /messages/by-id/CAE9k0PnZuZ3PVXSyQY91-53E8JKFcaSyknFqqU43r9MabKSYZA@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/59eb12c9c5a5aa980ed89363d143edad712d2c1d

Modified Files
--------------
contrib/pageinspect/btreefuncs.c | 2 +-
contrib/pageinspect/rawpage.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)