fix: improve debug messages

[knqyf263]

Overview

Improve debug messages

Before

$ trivy -debug image alpine:3.12
2021-09-19T21:20:34.363+0300    INFO    Detected OS: alpine
2021-09-19T21:20:34.363+0300    INFO    Detecting Alpine vulnerabilities...
...
2021-09-19T18:07:18.239+0300    DEBUG   Analysis error: unable to parse bin/arch: failed to parse bin/arch: EOF
2021-09-19T18:07:18.239+0300    DEBUG   Analysis error: unable to parse bin/ash: failed to parse bin/ash: EOF
2021-09-19T18:07:18.239+0300    DEBUG   Analysis error: unable to parse bin/bbconfig: failed to parse bin/bbconfig: EOF
2021-09-19T18:07:18.239+0300    DEBUG   Analysis error: unable to parse bin/base64: failed to parse bin/base64: EOF
2021-09-19T18:07:18.699+0300    DEBUG   Analysis error: unable to parse bin/chown: failed to parse bin/chown: EOF
2021-09-19T18:07:18.699+0300    DEBUG   Analysis error: unable to parse bin/chgrp: failed to parse bin/chgrp: EOF
2021-09-19T18:07:18.699+0300    DEBUG   Analysis error: unable to parse bin/conspy: failed to parse bin/conspy: EOF
2021-09-19T18:07:18.699+0300    DEBUG   Analysis error: unable to parse bin/chmod: failed to parse bin/chmod: EOF

After

$ trivy image aquasec/trivy:0.19.2
2021-09-19T21:20:34.363+0300    INFO    Detected OS: alpine
2021-09-19T21:20:34.363+0300    INFO    Detecting Alpine vulnerabilities...
2021-09-19T21:20:34.364+0300    INFO    Number of language-specific files: 1
2021-09-19T21:20:34.364+0300    INFO    Detecting gobinary vulnerabilities...

PRs

• fix(go/binary): ignore unrecognized exe error fanal#282
• fix(go/binary): check file mode fanal#281