adb: Do not look for bu in /system/bin when in recovery mode

This prevents breakage when /system is mounted while in recovery.

Change-Id: I4594d33969987cd1d17b4d865d6aca448596d0c1
Add Nokia vendor ID to adb and fastboot

Change-Id: I6bf1ea704f93c9de37c45a6edf8175d426708c7b