Fix incorrect error message in xlogreader.cHEADmaster

When neither BKPIMAGE_HAS_HOLE nor BKPIMAGE_COMPRESSED is set,
DecodeXLogRecord() checks that bimg_len needs to be equal to BLCKSZ.
However, the associated error message reported the data length
associated to a block (DecodedBkpBlock.data_len), and not the length of
the block (DecodedBkpBlock.bimg_len).

Oversight in 57aa5b2bb11a, probably due to some copy-paste from the
surroundings.

Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Discussion: https://postgr.es/m/CAJTYsWVz9ymE7aMt2ZiQvs1bxNvhjfTf+XaJEsdFw7MT5dvtYQ@mail.gmail.com
Backpatch-through: 14

0 files changed, 0 insertions, 0 deletions