Rearranged some iffy exception checking

Signed-off-by: mulhern <amulhern@redhat.com>
Get rid of old exception unpacking syntax

Signed-off-by: mulhern <amulhern@redhat.com>
Use the disk's name in log message

That must be what is wanted, also DeviceError does not have a name field.

Signed-off-by: mulhern <amulhern@redhat.com>
Don't get return values from communicate() if they are ignored

Signed-off-by: mulhern <amulhern@redhat.com>
Remove a lot of unused variables extracted from udev info

Signed-off-by: mulhern <amulhern@redhat.com>
Remove appendiceal assignments

These all look like they were valuable to some code once and that code went
away, but they remained.

Signed-off-by: mulhern <amulhern@redhat.com>
Be specific when catching exceptions

Signed-off-by: mulhern <amulhern@redhat.com>
Don't assign return value to unused variable

But keep the call, for the side-effects.

Signed-off-by: mulhern <amulhern@redhat.com>