Reland Skip F2FS formatting for dev option enabled devices

F2FS does not support page_size!=block_size configuration, and
dev option devices need to toggle between 4K/16K mode, hence F2FS
requires a data wipe every time page size changes. This is inconveinent,
skip F2FS formatting instead.

The original CL had a bug where `iter->blk_device` is accessed before
checking if `iter` is out of bounds. Fixed by flipping order of two
conditions in an && operator.

Test: th
Bug: 353436188

This reverts commit 642a98e2.

Change-Id: I89551f219efc44bad29a190edff5412a5cc67840