[2.12] drop failing corner-case check in logparser.py
aa-logprof errors out if it hits a log event for a non-existing profile while a profile file with the default filename for that non-existing profile exists. This can for example happen after adding a profile name to a profile if audit.log still contains events for the attachment-based profile name.
Since we ignore log events for non-existing profiles in general, drop the code for the special case "but a file matching the default filename for that non-existing profile exists" and also silently ignore events for this very special non-existing profile.
Also drop the now unused function get_profile_filename()
This is the 2.12 version of !296 (merged) - the only difference is the context of the removed
import os line.