Log security groups correctly

[mogren]

Description of changes:
Before:

[INFO] createENI: use primary interface's config, [0xc00003b680 0xc00003b6b0], subnet-0391a9d4a4d2cb999

After:

[INFO] Using same config as the primary interface for the new ENI
[INFO] Creating ENI with security groups: [sg-08f1036b507b30999 sg-0aa43d9d01804c999] in subnet: subnet-02d0c4ea9bd25d999

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[tiffanyfay]

Looks fine to me.