[gitian] Fix log2 symbol versioning

Summary:
I did 2 mistakes in D14484:

• I created a log2 wrapper to an older glibc version, but forget to tell the linter to use the wrapper
• I called the bot with a typo so it didn't run the gitian build in the diff

Actually use the wrapper so we don't pull the glibc 2.29 version of the log2 symbol.

Test Plan: Run the gitian builds

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D14499