xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

xfsprogs: remove incorrect l_sectBBsize assignment in xfs_repair

Commit e0607266 xfsprogs: add crc format support to repair

added a 2nd assignment to l_sectBBsize:

	log.l_sectBBsize = 1 << mp->m_sb.sb_logsectlog;

which is incorrect; sb_logsectlog is log2 of the sector size,
in bytes; l_sectBBsize is the size of the log sector in
512-byte units.

So for a 4k sector size log, we were assigning 4096 rather
than 8.  This broke xlog_find_tail, and caused xfs_repair
to think that a log was dirty even when it was clean:

"ERROR: The filesystem has valuable metadata changes in a log"

(xfs_logprint didn't have this error, so xfs_logprint -t
agreed that the filesystem really was clean).

Just remove the incorrect assignment; it was already properly
assigned about 12 lines prior:

        log.l_sectBBsize  = BTOBB(x.lbsize);

and things work again.

(This worked accidentally for 512-sector devices, because
we special-case those and set sb_logsectlog to "0" rather
than 9, so l_sectBBsize came out to "1" (as in 1 sector),
as it should have).

Reporteed-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Rich Johnston <rjohnston@sgi.com>