blessed-builds: Check the right changes file

The binary changes file can never pass the check since the dsc
referenced there is mangled by the mergechanges call.

f8614406 should have handled both
scripts but only handled the param case.

Mitigates: #37
1 job for master in 24 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #218010
librem5
build-native

00:00:24