xfs_scrub: actually iterate all the bulkstat records

xfs_scrub: actually iterate all the bulkstat records

In scan_ag_bulkstat, we have a for loop that iterates all the
xfs_bulkstat records in breq->bulkstat.  The loop condition test should
test against the array length, not the number of bits set in an
unrelated data structure.  If ocount > xi_alloccount then we miss some
inodes; if ocount < xi_alloccount then we've walked off the end of the
array.

Cc: <linux-xfs@vger.kernel.org> # v5.18.0
Fixes: 245c72a6eeb720 ("xfs_scrub: balance inode chunk scan across CPUs")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>