wifi-hal: fix -Wunreachable-code-loop-increment

This is part of a cleanup to fix instances of the
-Wunreachable-code-loop-increment warning, which is now
enabled under -Werror by default.

This isn't intended to be a functional change.

Bug: 150166387

Change-Id: Ic6484bce57ce620c8efcfe0490292496358f3030
CRs-Fixed: 2807097