pgsql: Print WAL position correctly in pg_rewind error message.

Print WAL position correctly in pg_rewind error message.

This has been wrong ever since pg_rewind was added. The if-branch just
above this, where we print the same error with an extra message supplied
by XLogReadRecord() got this right, but the variable name was wrong in the
else-branch. As a consequence, the error printed the WAL position as
0/0 if there was an error reading a WAL file.

Backpatch to 9.5, where pg_rewind was added.

Branch
------
REL_12_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/718e313244a9376d823b5efe421eb079474a6b20

Modified Files
--------------
src/bin/pg_rewind/parsexlog.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)