Actually, 'compressedlcs' stores compressed block count rather than
lcluster count. Therefore, the number of bits for shifting the count
should be 'LOG_BLOCK_SIZE' rather than 'lclusterbits' although current
lcluster size is 4K. The value of 'm_plen' will be wrong once we enable
the non 4K-sized lcluster.
Signed-off-by: Yue Hu <huyue2@xxxxxxxxxxx>