devel/tbb: Fix symlink creation during build

Temporary variable CC_BASENAME may not reflect actual COMPILER_TYPE on
environments that modify CC or COMPILER_TYPE through included files,
leading to creating a wrong symlink.

Evaluating CC in the post-extract target ensures it is up to date and
in line with COMPILER_TYPE.

PR: 263851
Reported by: Sean Champ <lab+bsd@thinkum.space>
MFH: 2022Q2