tc-testing: unbreak full listing of tdc testcases

the following command currently fails:

 [root@fedora tc-testing]# ./tdc.py -l
 The following test case IDs are not unique:
 {'6f5e'}
 Please correct them before continuing.

this happens because there are two tests having the same id:

 [root@fedora tc-testing]# grep -r 6f5e tc-tests/*
 tc-tests/actions/pedit.json:        "id": "6f5e",
 tc-tests/filters/basic.json:        "id": "6f5e",

fix it replacing the latest duplicate id with a brand new one:

 [root@fedora tc-testing]# sed -i 's/6f5e//1' tc-tests/filters/basic.json
 [root@fedora tc-testing]# ./tdc.py -i

Fixes: 4717b053

 ("tc-testing: Introduced tdc tests for basic filter")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>