ahci: fix integer sign extension bug

Reported by Coverity.

Change-Id: Ie7eef9570c89c69a05ba45169a0ea838f0d8e320
libbdev: fix IOCTL grant access bug

Reported by Coverity.

Change-Id: I34983312bebd9bf2449412b7dfa691ed208867ea
Kernel: correct a case of misleading indentation

Reported by Coverity.

Change-Id: If5d8a890052918f59fcc966759e4676fc4c894f0