Revert "UPSTREAM: ext4: add ext4_sb_block_valid() refactored out of ext4_inode_block_valid()"

This reverts commit daab1575.

Reason for revert: remove CLs not exist on android13-5.10-2023-03

Bug: 276221061
Change-Id: I1e027875269f0a703226c219e221815d5a9e0410
Signed-off-by: Robin Peng <robinpeng@google.com>