fix result logic

- a test may only be set to ok if no previous result exists
- a test must be set to failed always, even if it was previously set
  to ok
remove another place of evil env modification ☠☠☠

If the test name ends in 'uefi' it overwrites it with '1'
make UEFI a flag

UEFI_BIOS_DIR points to the location of the UEFI BIOS with MS key
refactor usb install a bit