PR #638 didn't correctly fix the code that fills in BTF info (e.g., source line) per instruction, when multiple programs appear in a section. This PR corrects that oversight.
coverage: 90.431% (+0.04%) from 90.39%
when pulling ea3587e32ec4231cfe670160c440e1b40887c49b on dthaler:fix-bpf
into 01d26e5c359e380fe7f3f0561ac9e877bc1f9ba3 on vbpf:main.
PR #638 didn't correctly fix the code that fills in BTF info (e.g., source line) per instruction, when multiple programs appear in a section. This PR corrects that oversight.