Enhance apf_disassembler to always print PASS/DROP labels.

This commit modifies the apf_disassembler utility to consistently print
the "PASS" and "DROP" labels, improving output clarity and making it
easier to understand the program's control flow.

Example outputs:

$ echo "" | apf_disassembler
       0: PASS
       1: DROP

$ echo "00" | apf_disassembler
       0: pass
       1: PASS
       2: DROP

Test: TH
Change-Id: Ie25103a1e4d86a3ed95ea3f6691278bbc2274978
1 file changed