power: pm8921-bms: fix approach fcc

There is a bug in the code where upon end of charging, the delta
fcc is not divided by 100. This causes incorrect fcc values to be
learnt.

Fix it by correctly diving the increase/decrease by 100 for new
fcc estimation.

Change-Id: I8426a450075dd4d9f1ff02009ecbf39bae8aca30
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>