fsck.ubifs: check and correct the space statistics

fsck.ubifs: check and correct the space statistics

This is the 12/18 step of fsck. Check and correct the space statistics.
There could be following steps and possible errors:
 Step 1. Exit for check mode, if %FR_LPT_CORRUPTED or %FR_LPT_INCORRECT
 is set in lpt status, the exit code should have %FSCK_UNCORRECTED.
 Step 2. Check lpt status, if %FR_LPT_CORRUPTED is set in lpt status,
 normal mode with 'no' answer will exit, other modes will rebuild lpt.
 Step 3. Traverse LPT nodes, check the correctness of nnode and pnode,
 compare LEB scanning result with LEB properties.
  a. LPT node is corrupted, normal mode with 'no' answer will exit,
     rebuild lpt for other modes.
  b. Incorrect nnode/pnode, normal mode with 'no' answer will exit,
     other other modes will correct the nnode/pnode.
  c. Inconsistent comparing result, normal mode with 'no' answer
     will exit, other modes will correct the space statistics.
 Step 4. Check and correct the lprops table information.
 Step 5. Set gc lnum(ubifs_rcvry_gc_commit / take_gc_lnum).

Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>