pca9468_charger: double check for new_iin when new_iin apply done

If new_iin can't be update during applying previous iin.
Add a new_iin check in return loop function to apply correct iin.

Note:
Also correct some log patterm for iin related flow.

Bug: 194757446
Signed-off-by: Wasb Liu <wasbliu@google.com>
Change-Id: I67addedb9fa9a9f4bcf32f5f57b1573da8dd30b8