releasetools: Fix the bug when generating care_map.txt.

Commit f1a13180 intended to remove the
verity blocks from care_map.txt, but it added new code without removing
the old one. This leads to a malformed care_map.txt and causes
update_verifier failure.

Bug: 34391662
Test: 'm -j dist' gives a TF.zip with 4-line META/care_map.txt (as
      opposed to a 6-line file).

Change-Id: I7ff1aa525795c4b049af54c1755b0f0ea84f7e0e